[ aws . wafv2 ]

create-web-acl

Description

Creates a WebACL per the specifications provided.

A web ACL defines a collection of rules to use to inspect and control web requests. Each rule has an action defined (allow, block, or count) for requests that match the statement of the rule. In the web ACL, you assign a default action to take (allow, block) for any request that does not match any of the rules. The rules in a web ACL can be a combination of the types Rule , RuleGroup , and managed rule group. You can associate a web ACL with one or more Amazon Web Services resources to protect. The resources can be an Amazon CloudFront distribution, an Amazon API Gateway REST API, an Application Load Balancer, an AppSync GraphQL API, an Amazon Cognito user pool, an App Runner service, or an Amazon Web Services Verified Access instance.

See also: AWS API Documentation

Synopsis

  create-web-acl
--name <value>
--scope <value>
--default-action <value>
[--description <value>]
[--rules <value>]
--visibility-config <value>
[--tags <value>]
[--custom-response-bodies <value>]
[--captcha-config <value>]
[--challenge-config <value>]
[--token-domains <value>]
[--association-config <value>]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]
[--debug]
[--endpoint-url <value>]
[--no-verify-ssl]
[--no-paginate]
[--output <value>]
[--query <value>]
[--profile <value>]
[--region <value>]
[--version <value>]
[--color <value>]
[--no-sign-request]
[--ca-bundle <value>]
[--cli-read-timeout <value>]
[--cli-connect-timeout <value>]
[--cli-binary-format <value>]
[--no-cli-pager]
[--cli-auto-prompt]
[--no-cli-auto-prompt]

Options

--name (string)

The name of the web ACL. You cannot change the name of a web ACL after you create it.

--scope (string)

Specifies whether this is for an Amazon CloudFront distribution or for a regional application. A regional application can be an Application Load Balancer (ALB), an Amazon API Gateway REST API, an AppSync GraphQL API, an Amazon Cognito user pool, an App Runner service, or an Amazon Web Services Verified Access instance.

To work with CloudFront, you must also specify the Region US East (N. Virginia) as follows:

  • CLI - Specify the Region when you use the CloudFront scope: --scope=CLOUDFRONT --region=us-east-1 .
  • API and SDKs - For all calls, use the Region endpoint us-east-1.

Possible values:

  • CLOUDFRONT
  • REGIONAL

--default-action (structure)

The action to perform if none of the Rules contained in the WebACL match.

Block -> (structure)

Specifies that WAF should block requests by default.

CustomResponse -> (structure)

Defines a custom response for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

ResponseCode -> (integer)

The HTTP status code to return to the client.

For a list of status codes that you can use in your custom responses, see Supported status codes for custom response in the WAF Developer Guide .

CustomResponseBodyKey -> (string)

References the response body that you want WAF to return to the web request client. You can define a custom response for a rule action or a default web ACL action that is set to block. To do this, you first define the response body key and value in the CustomResponseBodies setting for the WebACL or RuleGroup where you want to use it. Then, in the rule action or web ACL default action BlockAction setting, you reference the response body using this key.

ResponseHeaders -> (list)

The HTTP headers to use in the response. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Allow -> (structure)

Specifies that WAF should allow requests by default.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

JSON Syntax:

{
  "Block": {
    "CustomResponse": {
      "ResponseCode": integer,
      "CustomResponseBodyKey": "string",
      "ResponseHeaders": [
        {
          "Name": "string",
          "Value": "string"
        }
        ...
      ]
    }
  },
  "Allow": {
    "CustomRequestHandling": {
      "InsertHeaders": [
        {
          "Name": "string",
          "Value": "string"
        }
        ...
      ]
    }
  }
}

--description (string)

A description of the web ACL that helps with identification.

--rules (list)

The Rule statements used to identify the web requests that you want to allow, block, or count. Each rule includes one top-level statement that WAF uses to identify matching web requests, and parameters that govern how WAF handles them.

(structure)

A single rule, which you can use in a WebACL or RuleGroup to identify web requests that you want to allow, block, or count. Each rule includes one top-level Statement that WAF uses to identify matching web requests, and parameters that govern how WAF handles them.

Name -> (string)

The name of the rule. You can’t change the name of a Rule after you create it.

Priority -> (integer)

If you define more than one Rule in a WebACL , WAF evaluates each request against the Rules in order based on the value of Priority . WAF processes rules with lower priority first. The priorities don’t need to be consecutive, but they must all be different.

Statement -> (structure)

The WAF processing statement for the rule, for example ByteMatchStatement or SizeConstraintStatement .

ByteMatchStatement -> (structure)

A rule statement that defines a string match search for WAF to apply to web requests. The byte match statement provides the bytes to search for, the location in requests that you want WAF to search, and other settings. The bytes to search for are typically a string that corresponds with ASCII characters. In the WAF console and the developer guide, this is called a string match statement.

SearchString -> (blob)

A string value that you want WAF to search for. WAF searches only in the part of web requests that you designate for inspection in FieldToMatch . The maximum length of the value is 200 bytes.

Valid values depend on the component that you specify for inspection in FieldToMatch :

  • Method : The HTTP method that you want WAF to search for. This indicates the type of operation specified in the request.
  • UriPath : The value that you want WAF to search for in the URI path, for example, /images/daily-ad.jpg .

If SearchString includes alphabetic characters A-Z and a-z, note that the value is case sensitive.

If you’re using the WAF API

Specify a base64-encoded version of the value. The maximum length of the value before you base64-encode it is 200 bytes.

For example, suppose the value of Type is HEADER and the value of Data is User-Agent . If you want to search the User-Agent header for the value BadBot , you base64-encode BadBot using MIME base64-encoding and include the resulting value, QmFkQm90 , in the value of SearchString .

If you’re using the CLI or one of the Amazon Web Services SDKs

The value that you want WAF to search for. The SDK automatically base64 encodes the value.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

PositionalConstraint -> (string)

The area within the portion of the web request that you want WAF to search for SearchString . Valid values include the following:

CONTAINS

The specified part of the web request must include the value of SearchString , but the location doesn’t matter.

CONTAINS_WORD

The specified part of the web request must include the value of SearchString , and SearchString must contain only alphanumeric characters or underscore (A-Z, a-z, 0-9, or _). In addition, SearchString must be a word, which means that both of the following are true:

  • SearchString is at the beginning of the specified part of the web request or is preceded by a character other than an alphanumeric character or underscore (_). Examples include the value of a header and ;BadBot .
  • SearchString is at the end of the specified part of the web request or is followed by a character other than an alphanumeric character or underscore (_), for example, BadBot; and -BadBot; .
EXACTLY

The value of the specified part of the web request must exactly match the value of SearchString .

STARTS_WITH

The value of SearchString must appear at the beginning of the specified part of the web request.

ENDS_WITH

The value of SearchString must appear at the end of the specified part of the web request.

SqliMatchStatement -> (structure)

A rule statement that inspects for malicious SQL code. Attackers insert malicious SQL code into web requests to do things like modify your database or extract data from it.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SensitivityLevel -> (string)

The sensitivity that you want WAF to use to inspect for SQL injection attacks.

HIGH detects more attacks, but might generate more false positives, especially if your web requests frequently contain unusual strings. For information about identifying and mitigating false positives, see Testing and tuning in the WAF Developer Guide .

LOW is generally a better choice for resources that already have other protections against SQL injection attacks or that have a low tolerance for false positives.

Default: LOW

XssMatchStatement -> (structure)

A rule statement that inspects for cross-site scripting (XSS) attacks. In XSS attacks, the attacker uses vulnerabilities in a benign website as a vehicle to inject malicious client-site scripts into other legitimate web browsers.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SizeConstraintStatement -> (structure)

A rule statement that compares a number of bytes against the size of a request component, using a comparison operator, such as greater than (>) or less than (<). For example, you can use a size constraint statement to look for query strings that are longer than 100 bytes.

If you configure WAF to inspect the request body, WAF inspects only the number of bytes of the body up to the limit for the web ACL. By default, for regional web ACLs, this limit is 8 KB (8,192 kilobytes) and for CloudFront web ACLs, this limit is 16 KB (16,384 kilobytes). For CloudFront web ACLs, you can increase the limit in the web ACL AssociationConfig , for additional fees. If you know that the request body for your web requests should never exceed the inspection limit, you could use a size constraint statement to block requests that have a larger request body size.

If you choose URI for the value of Part of the request to filter on, the slash (/) in the URI counts as one character. For example, the URI /logo.jpg is nine characters long.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

ComparisonOperator -> (string)

The operator to use to compare the request part to the size setting.

Size -> (long)

The size, in byte, to compare to the request part, after any transformations.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

GeoMatchStatement -> (structure)

A rule statement that labels web requests by country and region and that matches against web requests based on country code. A geo match rule labels every request that it inspects regardless of whether it finds a match.

  • To manage requests only by country, you can use this statement by itself and specify the countries that you want to match against in the CountryCodes array.
  • Otherwise, configure your geo match rule with Count action so that it only labels requests. Then, add one or more label match rules to run after the geo match rule and configure them to match against the geographic labels and handle the requests as needed.

WAF labels requests using the alpha-2 country and region codes from the International Organization for Standardization (ISO) 3166 standard. WAF determines the codes using either the IP address in the web request origin or, if you specify it, the address in the geo match ForwardedIPConfig .

If you use the web request origin, the label formats are awswaf:clientip:geo:region:<ISO country code>-<ISO region code> and awswaf:clientip:geo:country:<ISO country code> .

If you use a forwarded IP address, the label formats are awswaf:forwardedip:geo:region:<ISO country code>-<ISO region code> and awswaf:forwardedip:geo:country:<ISO country code> .

For additional details, see Geographic match rule statement in the WAF Developer Guide .

CountryCodes -> (list)

An array of two-character country codes that you want to match against, for example, [ "US", "CN" ] , from the alpha-2 country ISO codes of the ISO 3166 international standard.

When you use a geo match statement just for the region and country labels that it adds to requests, you still have to supply a country code for the rule to evaluate. In this case, you configure the rule to only count matching requests, but it will still generate logging and count metrics for any matches. You can reduce the logging and metrics that the rule produces by specifying a country that’s unlikely to be a source of traffic to your site.

(string)

ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

RuleGroupReferenceStatement -> (structure)

A rule statement used to run the rules that are defined in a RuleGroup . To use this, create a rule group with your rules, then provide the ARN of the rule group in this statement.

You cannot nest a RuleGroupReferenceStatement , for example for use inside a NotStatement or OrStatement . You can only use a rule group reference statement at the top level inside a web ACL.

ARN -> (string)

The Amazon Resource Name (ARN) of the entity.

ExcludedRules -> (list)

Rules in the referenced rule group whose actions are set to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

(structure)

Specifies a single rule in a rule group whose action you want to override to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

Name -> (string)

The name of the rule whose action you want to override to Count .

RuleActionOverrides -> (list)

Action settings to use in the place of the rule actions that are configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

(structure)

Action setting to use in the place of a rule action that is configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

Name -> (string)

The name of the rule to override.

ActionToUse -> (structure)

The override action to use, in place of the configured action of the rule in the rule group.

Block -> (structure)

Instructs WAF to block the web request.

CustomResponse -> (structure)

Defines a custom response for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

ResponseCode -> (integer)

The HTTP status code to return to the client.

For a list of status codes that you can use in your custom responses, see Supported status codes for custom response in the WAF Developer Guide .

CustomResponseBodyKey -> (string)

References the response body that you want WAF to return to the web request client. You can define a custom response for a rule action or a default web ACL action that is set to block. To do this, you first define the response body key and value in the CustomResponseBodies setting for the WebACL or RuleGroup where you want to use it. Then, in the rule action or web ACL default action BlockAction setting, you reference the response body using this key.

ResponseHeaders -> (list)

The HTTP headers to use in the response. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Allow -> (structure)

Instructs WAF to allow the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Count -> (structure)

Instructs WAF to count the web request and then continue evaluating the request using the remaining rules in the web ACL.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Captcha -> (structure)

Instructs WAF to run a CAPTCHA check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the CAPTCHA inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Challenge -> (structure)

Instructs WAF to run a Challenge check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the challenge inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

IPSetReferenceStatement -> (structure)

A rule statement used to detect web requests coming from particular IP addresses or address ranges. To use this, create an IPSet that specifies the addresses you want to detect, then use the ARN of that set in this statement. To create an IP set, see CreateIPSet .

Each IP set rule statement references an IP set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the IPSet that this statement references.

IPSetForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Position -> (string)

The position in the header to search for the IP address. The header can contain IP addresses of the original client and also of proxies. For example, the header value could be 10.1.1.1, 127.0.0.0, 10.10.10.10 where the first IP address identifies the original client and the rest identify proxies that the request went through.

The options for this setting are the following:

  • FIRST - Inspect the first IP address in the list of IP addresses in the header. This is usually the client’s original IP.
  • LAST - Inspect the last IP address in the list of IP addresses in the header.
  • ANY - Inspect all IP addresses in the header for a match. If the header contains more than 10 IP addresses, WAF inspects the last 10.

RegexPatternSetReferenceStatement -> (structure)

A rule statement used to search web request components for matches with regular expressions. To use this, create a RegexPatternSet that specifies the expressions that you want to detect, then use the ARN of that set in this statement. A web request matches the pattern set rule statement if the request component matches any of the patterns in the set. To create a regex pattern set, see CreateRegexPatternSet .

Each regex pattern set rule statement references a regex pattern set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the RegexPatternSet that this statement references.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

RateBasedStatement -> (structure)

A rate-based rule counts incoming requests and rate limits requests when they are coming at too fast a rate. The rule categorizes requests according to your aggregation criteria, collects them into aggregation instances, and counts and rate limits the requests for each instance.

You can specify individual aggregation keys, like IP address or HTTP method. You can also specify aggregation key combinations, like IP address and HTTP method, or HTTP method, query argument, and cookie.

Each unique set of values for the aggregation keys that you specify is a separate aggregation instance, with the value from each key contributing to the aggregation instance definition.

For example, assume the rule evaluates web requests with the following IP address and HTTP method values:

  • IP address 10.1.1.1, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET
  • IP address 127.0.0.0, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET

The rule would create different aggregation instances according to your aggregation criteria, for example:

  • If the aggregation criteria is just the IP address, then each individual address is an aggregation instance, and WAF counts requests separately for each. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1: count 3
    • IP address 127.0.0.0: count 1
  • If the aggregation criteria is HTTP method, then each individual HTTP method is an aggregation instance. The aggregation instances and request counts for our example would be the following:
    • HTTP method POST: count 2
    • HTTP method GET: count 2
  • If the aggregation criteria is IP address and HTTP method, then each IP address and each HTTP method would contribute to the combined aggregation instance. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1, HTTP method POST: count 1
    • IP address 10.1.1.1, HTTP method GET: count 2
    • IP address 127.0.0.0, HTTP method POST: count 1

For any n-tuple of aggregation keys, each unique combination of values for the keys defines a separate aggregation instance, which WAF counts and rate-limits individually.

You can optionally nest another statement inside the rate-based statement, to narrow the scope of the rule so that it only counts and rate limits requests that match the nested statement. You can use this nested scope-down statement in conjunction with your aggregation key specifications or you can just count and rate limit all requests that match the scope-down statement, without additional aggregation. When you choose to just manage all requests that match a scope-down statement, the aggregation instance is singular for the rule.

You cannot nest a RateBasedStatement inside another statement, for example inside a NotStatement or OrStatement . You can define a RateBasedStatement inside a web ACL and inside a rule group.

For additional information about the options, see Rate limiting web requests using rate-based rules in the WAF Developer Guide .

If you only aggregate on the individual IP address or forwarded IP address, you can retrieve the list of IP addresses that WAF is currently rate limiting for a rule through the API call GetRateBasedStatementManagedKeys . This option is not available for other aggregation configurations.

WAF tracks and manages web requests separately for each instance of a rate-based rule that you use. For example, if you provide the same rate-based rule settings in two web ACLs, each of the two rule statements represents a separate instance of the rate-based rule and gets its own tracking and management by WAF. If you define a rate-based rule inside a rule group, and then use that rule group in multiple places, each use creates a separate instance of the rate-based rule that gets its own tracking and management by WAF.

Limit -> (long)

The limit on requests per 5-minute period for a single aggregation instance for the rate-based rule. If the rate-based statement includes a ScopeDownStatement , this limit is applied only to the requests that match the statement.

Examples:

  • If you aggregate on just the IP address, this is the limit on requests from any single IP address.
  • If you aggregate on the HTTP method and the query argument name “city”, then this is the limit on requests for any single method, city pair.

AggregateKeyType -> (string)

Setting that indicates how to aggregate the request counts.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.
  • CONSTANT - Count and limit the requests that match the rate-based rule’s scope-down statement. With this option, the counted requests aren’t further aggregated. The scope-down statement is the only specification used. When the count of all requests that satisfy the scope-down statement goes over the limit, WAF applies the rule action to all requests that satisfy the scope-down statement. With this option, you must configure the ScopeDownStatement property.
  • CUSTOM_KEYS - Aggregate the request counts using one or more web request components as the aggregate keys. With this option, you must specify the aggregate keys in the CustomKeys property. To aggregate on only the IP address or only the forwarded IP address, don’t use custom keys. Instead, set the aggregate key type to IP or FORWARDED_IP .
  • FORWARDED_IP - Aggregate the request counts on the first IP address in an HTTP header. With this option, you must specify the header to use in the ForwardedIPConfig property. To aggregate on a combination of the forwarded IP address with other aggregate keys, use CUSTOM_KEYS .
  • IP - Aggregate the request counts on the IP address from the web request origin. To aggregate on a combination of the IP address with other aggregate keys, use CUSTOM_KEYS .

ScopeDownStatement -> (structure)

An optional nested statement that narrows the scope of the web requests that are evaluated and managed by the rate-based statement. When you use a scope-down statement, the rate-based rule only tracks and rate limits requests that match the scope-down statement. You can use any nestable Statement in the scope-down statement, and you can nest statements at any level, the same as you can for a rule statement.

ByteMatchStatement -> (structure)

A rule statement that defines a string match search for WAF to apply to web requests. The byte match statement provides the bytes to search for, the location in requests that you want WAF to search, and other settings. The bytes to search for are typically a string that corresponds with ASCII characters. In the WAF console and the developer guide, this is called a string match statement.

SearchString -> (blob)

A string value that you want WAF to search for. WAF searches only in the part of web requests that you designate for inspection in FieldToMatch . The maximum length of the value is 200 bytes.

Valid values depend on the component that you specify for inspection in FieldToMatch :

  • Method : The HTTP method that you want WAF to search for. This indicates the type of operation specified in the request.
  • UriPath : The value that you want WAF to search for in the URI path, for example, /images/daily-ad.jpg .

If SearchString includes alphabetic characters A-Z and a-z, note that the value is case sensitive.

If you’re using the WAF API

Specify a base64-encoded version of the value. The maximum length of the value before you base64-encode it is 200 bytes.

For example, suppose the value of Type is HEADER and the value of Data is User-Agent . If you want to search the User-Agent header for the value BadBot , you base64-encode BadBot using MIME base64-encoding and include the resulting value, QmFkQm90 , in the value of SearchString .

If you’re using the CLI or one of the Amazon Web Services SDKs

The value that you want WAF to search for. The SDK automatically base64 encodes the value.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

PositionalConstraint -> (string)

The area within the portion of the web request that you want WAF to search for SearchString . Valid values include the following:

CONTAINS

The specified part of the web request must include the value of SearchString , but the location doesn’t matter.

CONTAINS_WORD

The specified part of the web request must include the value of SearchString , and SearchString must contain only alphanumeric characters or underscore (A-Z, a-z, 0-9, or _). In addition, SearchString must be a word, which means that both of the following are true:

  • SearchString is at the beginning of the specified part of the web request or is preceded by a character other than an alphanumeric character or underscore (_). Examples include the value of a header and ;BadBot .
  • SearchString is at the end of the specified part of the web request or is followed by a character other than an alphanumeric character or underscore (_), for example, BadBot; and -BadBot; .
EXACTLY

The value of the specified part of the web request must exactly match the value of SearchString .

STARTS_WITH

The value of SearchString must appear at the beginning of the specified part of the web request.

ENDS_WITH

The value of SearchString must appear at the end of the specified part of the web request.

SqliMatchStatement -> (structure)

A rule statement that inspects for malicious SQL code. Attackers insert malicious SQL code into web requests to do things like modify your database or extract data from it.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SensitivityLevel -> (string)

The sensitivity that you want WAF to use to inspect for SQL injection attacks.

HIGH detects more attacks, but might generate more false positives, especially if your web requests frequently contain unusual strings. For information about identifying and mitigating false positives, see Testing and tuning in the WAF Developer Guide .

LOW is generally a better choice for resources that already have other protections against SQL injection attacks or that have a low tolerance for false positives.

Default: LOW

XssMatchStatement -> (structure)

A rule statement that inspects for cross-site scripting (XSS) attacks. In XSS attacks, the attacker uses vulnerabilities in a benign website as a vehicle to inject malicious client-site scripts into other legitimate web browsers.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SizeConstraintStatement -> (structure)

A rule statement that compares a number of bytes against the size of a request component, using a comparison operator, such as greater than (>) or less than (<). For example, you can use a size constraint statement to look for query strings that are longer than 100 bytes.

If you configure WAF to inspect the request body, WAF inspects only the number of bytes of the body up to the limit for the web ACL. By default, for regional web ACLs, this limit is 8 KB (8,192 kilobytes) and for CloudFront web ACLs, this limit is 16 KB (16,384 kilobytes). For CloudFront web ACLs, you can increase the limit in the web ACL AssociationConfig , for additional fees. If you know that the request body for your web requests should never exceed the inspection limit, you could use a size constraint statement to block requests that have a larger request body size.

If you choose URI for the value of Part of the request to filter on, the slash (/) in the URI counts as one character. For example, the URI /logo.jpg is nine characters long.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

ComparisonOperator -> (string)

The operator to use to compare the request part to the size setting.

Size -> (long)

The size, in byte, to compare to the request part, after any transformations.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

GeoMatchStatement -> (structure)

A rule statement that labels web requests by country and region and that matches against web requests based on country code. A geo match rule labels every request that it inspects regardless of whether it finds a match.

  • To manage requests only by country, you can use this statement by itself and specify the countries that you want to match against in the CountryCodes array.
  • Otherwise, configure your geo match rule with Count action so that it only labels requests. Then, add one or more label match rules to run after the geo match rule and configure them to match against the geographic labels and handle the requests as needed.

WAF labels requests using the alpha-2 country and region codes from the International Organization for Standardization (ISO) 3166 standard. WAF determines the codes using either the IP address in the web request origin or, if you specify it, the address in the geo match ForwardedIPConfig .

If you use the web request origin, the label formats are awswaf:clientip:geo:region:<ISO country code>-<ISO region code> and awswaf:clientip:geo:country:<ISO country code> .

If you use a forwarded IP address, the label formats are awswaf:forwardedip:geo:region:<ISO country code>-<ISO region code> and awswaf:forwardedip:geo:country:<ISO country code> .

For additional details, see Geographic match rule statement in the WAF Developer Guide .

CountryCodes -> (list)

An array of two-character country codes that you want to match against, for example, [ "US", "CN" ] , from the alpha-2 country ISO codes of the ISO 3166 international standard.

When you use a geo match statement just for the region and country labels that it adds to requests, you still have to supply a country code for the rule to evaluate. In this case, you configure the rule to only count matching requests, but it will still generate logging and count metrics for any matches. You can reduce the logging and metrics that the rule produces by specifying a country that’s unlikely to be a source of traffic to your site.

(string)

ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

RuleGroupReferenceStatement -> (structure)

A rule statement used to run the rules that are defined in a RuleGroup . To use this, create a rule group with your rules, then provide the ARN of the rule group in this statement.

You cannot nest a RuleGroupReferenceStatement , for example for use inside a NotStatement or OrStatement . You can only use a rule group reference statement at the top level inside a web ACL.

ARN -> (string)

The Amazon Resource Name (ARN) of the entity.

ExcludedRules -> (list)

Rules in the referenced rule group whose actions are set to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

(structure)

Specifies a single rule in a rule group whose action you want to override to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

Name -> (string)

The name of the rule whose action you want to override to Count .

RuleActionOverrides -> (list)

Action settings to use in the place of the rule actions that are configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

(structure)

Action setting to use in the place of a rule action that is configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

Name -> (string)

The name of the rule to override.

ActionToUse -> (structure)

The override action to use, in place of the configured action of the rule in the rule group.

Block -> (structure)

Instructs WAF to block the web request.

CustomResponse -> (structure)

Defines a custom response for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

ResponseCode -> (integer)

The HTTP status code to return to the client.

For a list of status codes that you can use in your custom responses, see Supported status codes for custom response in the WAF Developer Guide .

CustomResponseBodyKey -> (string)

References the response body that you want WAF to return to the web request client. You can define a custom response for a rule action or a default web ACL action that is set to block. To do this, you first define the response body key and value in the CustomResponseBodies setting for the WebACL or RuleGroup where you want to use it. Then, in the rule action or web ACL default action BlockAction setting, you reference the response body using this key.

ResponseHeaders -> (list)

The HTTP headers to use in the response. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Allow -> (structure)

Instructs WAF to allow the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Count -> (structure)

Instructs WAF to count the web request and then continue evaluating the request using the remaining rules in the web ACL.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Captcha -> (structure)

Instructs WAF to run a CAPTCHA check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the CAPTCHA inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Challenge -> (structure)

Instructs WAF to run a Challenge check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the challenge inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

IPSetReferenceStatement -> (structure)

A rule statement used to detect web requests coming from particular IP addresses or address ranges. To use this, create an IPSet that specifies the addresses you want to detect, then use the ARN of that set in this statement. To create an IP set, see CreateIPSet .

Each IP set rule statement references an IP set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the IPSet that this statement references.

IPSetForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Position -> (string)

The position in the header to search for the IP address. The header can contain IP addresses of the original client and also of proxies. For example, the header value could be 10.1.1.1, 127.0.0.0, 10.10.10.10 where the first IP address identifies the original client and the rest identify proxies that the request went through.

The options for this setting are the following:

  • FIRST - Inspect the first IP address in the list of IP addresses in the header. This is usually the client’s original IP.
  • LAST - Inspect the last IP address in the list of IP addresses in the header.
  • ANY - Inspect all IP addresses in the header for a match. If the header contains more than 10 IP addresses, WAF inspects the last 10.

RegexPatternSetReferenceStatement -> (structure)

A rule statement used to search web request components for matches with regular expressions. To use this, create a RegexPatternSet that specifies the expressions that you want to detect, then use the ARN of that set in this statement. A web request matches the pattern set rule statement if the request component matches any of the patterns in the set. To create a regex pattern set, see CreateRegexPatternSet .

Each regex pattern set rule statement references a regex pattern set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the RegexPatternSet that this statement references.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

RateBasedStatement -> (structure)

A rate-based rule counts incoming requests and rate limits requests when they are coming at too fast a rate. The rule categorizes requests according to your aggregation criteria, collects them into aggregation instances, and counts and rate limits the requests for each instance.

You can specify individual aggregation keys, like IP address or HTTP method. You can also specify aggregation key combinations, like IP address and HTTP method, or HTTP method, query argument, and cookie.

Each unique set of values for the aggregation keys that you specify is a separate aggregation instance, with the value from each key contributing to the aggregation instance definition.

For example, assume the rule evaluates web requests with the following IP address and HTTP method values:

  • IP address 10.1.1.1, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET
  • IP address 127.0.0.0, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET

The rule would create different aggregation instances according to your aggregation criteria, for example:

  • If the aggregation criteria is just the IP address, then each individual address is an aggregation instance, and WAF counts requests separately for each. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1: count 3
    • IP address 127.0.0.0: count 1
  • If the aggregation criteria is HTTP method, then each individual HTTP method is an aggregation instance. The aggregation instances and request counts for our example would be the following:
    • HTTP method POST: count 2
    • HTTP method GET: count 2
  • If the aggregation criteria is IP address and HTTP method, then each IP address and each HTTP method would contribute to the combined aggregation instance. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1, HTTP method POST: count 1
    • IP address 10.1.1.1, HTTP method GET: count 2
    • IP address 127.0.0.0, HTTP method POST: count 1

For any n-tuple of aggregation keys, each unique combination of values for the keys defines a separate aggregation instance, which WAF counts and rate-limits individually.

You can optionally nest another statement inside the rate-based statement, to narrow the scope of the rule so that it only counts and rate limits requests that match the nested statement. You can use this nested scope-down statement in conjunction with your aggregation key specifications or you can just count and rate limit all requests that match the scope-down statement, without additional aggregation. When you choose to just manage all requests that match a scope-down statement, the aggregation instance is singular for the rule.

You cannot nest a RateBasedStatement inside another statement, for example inside a NotStatement or OrStatement . You can define a RateBasedStatement inside a web ACL and inside a rule group.

For additional information about the options, see Rate limiting web requests using rate-based rules in the WAF Developer Guide .

If you only aggregate on the individual IP address or forwarded IP address, you can retrieve the list of IP addresses that WAF is currently rate limiting for a rule through the API call GetRateBasedStatementManagedKeys . This option is not available for other aggregation configurations.

WAF tracks and manages web requests separately for each instance of a rate-based rule that you use. For example, if you provide the same rate-based rule settings in two web ACLs, each of the two rule statements represents a separate instance of the rate-based rule and gets its own tracking and management by WAF. If you define a rate-based rule inside a rule group, and then use that rule group in multiple places, each use creates a separate instance of the rate-based rule that gets its own tracking and management by WAF.

Limit -> (long)

The limit on requests per 5-minute period for a single aggregation instance for the rate-based rule. If the rate-based statement includes a ScopeDownStatement , this limit is applied only to the requests that match the statement.

Examples:

  • If you aggregate on just the IP address, this is the limit on requests from any single IP address.
  • If you aggregate on the HTTP method and the query argument name “city”, then this is the limit on requests for any single method, city pair.

AggregateKeyType -> (string)

Setting that indicates how to aggregate the request counts.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.
  • CONSTANT - Count and limit the requests that match the rate-based rule’s scope-down statement. With this option, the counted requests aren’t further aggregated. The scope-down statement is the only specification used. When the count of all requests that satisfy the scope-down statement goes over the limit, WAF applies the rule action to all requests that satisfy the scope-down statement. With this option, you must configure the ScopeDownStatement property.
  • CUSTOM_KEYS - Aggregate the request counts using one or more web request components as the aggregate keys. With this option, you must specify the aggregate keys in the CustomKeys property. To aggregate on only the IP address or only the forwarded IP address, don’t use custom keys. Instead, set the aggregate key type to IP or FORWARDED_IP .
  • FORWARDED_IP - Aggregate the request counts on the first IP address in an HTTP header. With this option, you must specify the header to use in the ForwardedIPConfig property. To aggregate on a combination of the forwarded IP address with other aggregate keys, use CUSTOM_KEYS .
  • IP - Aggregate the request counts on the IP address from the web request origin. To aggregate on a combination of the IP address with other aggregate keys, use CUSTOM_KEYS .

( … recursive … )ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

This is required if you specify a forwarded IP in the rule’s aggregate key settings.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

CustomKeys -> (list)

Specifies the aggregate keys to use in a rate-base rule.

(structure)

Specifies a single custom aggregate key for a rate-base rule.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.

Header -> (structure)

Use the value of a header in the request as an aggregate key. Each distinct value in the header contributes to the aggregation instance. If you use a single header as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the header to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

Cookie -> (structure)

Use the value of a cookie in the request as an aggregate key. Each distinct value in the cookie contributes to the aggregation instance. If you use a single cookie as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the cookie to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

QueryArgument -> (structure)

Use the specified query argument as an aggregate key. Each distinct value for the named query argument contributes to the aggregation instance. If you use a single query argument as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the query argument to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

QueryString -> (structure)

Use the request’s query string as an aggregate key. Each distinct string contributes to the aggregation instance. If you use just the query string as your custom key, then each string fully defines an aggregation instance.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

HTTPMethod -> (structure)

Use the request’s HTTP method as an aggregate key. Each distinct HTTP method contributes to the aggregation instance. If you use just the HTTP method as your custom key, then each method fully defines an aggregation instance.

ForwardedIP -> (structure)

Use the first IP address in an HTTP header as an aggregate key. Each distinct forwarded IP address contributes to the aggregation instance.

When you specify an IP or forwarded IP in the custom key settings, you must also specify at least one other key to use. You can aggregate on only the forwarded IP address by specifying FORWARDED_IP in your rate-based statement’s AggregateKeyType .

With this option, you must specify the header to use in the rate-based rule’s ForwardedIPConfig property.

IP -> (structure)

Use the request’s originating IP address as an aggregate key. Each distinct IP address contributes to the aggregation instance.

When you specify an IP or forwarded IP in the custom key settings, you must also specify at least one other key to use. You can aggregate on only the IP address by specifying IP in your rate-based statement’s AggregateKeyType .

LabelNamespace -> (structure)

Use the specified label namespace as an aggregate key. Each distinct fully qualified label name that has the specified label namespace contributes to the aggregation instance. If you use just one label namespace as your custom key, then each label name fully defines an aggregation instance.

This uses only labels that have been added to the request by rules that are evaluated before this rate-based rule in the web ACL.

For information about label namespaces and names, see Label syntax and naming requirements in the WAF Developer Guide .

Namespace -> (string)

The namespace to use for aggregation.

AndStatement -> (structure)

A logical rule statement used to combine other rule statements with AND logic. You provide more than one Statement within the AndStatement .

Statements -> (list)

The statements to combine with AND logic. You can use any statements that can be nested.

( … recursive … )

OrStatement -> (structure)

A logical rule statement used to combine other rule statements with OR logic. You provide more than one Statement within the OrStatement .

Statements -> (list)

The statements to combine with OR logic. You can use any statements that can be nested.

( … recursive … )

NotStatement -> (structure)

A logical rule statement used to negate the results of another rule statement. You provide one Statement within the NotStatement .

( … recursive … )

ManagedRuleGroupStatement -> (structure)

A rule statement used to run the rules that are defined in a managed rule group. To use this, provide the vendor name and the name of the rule group in this statement. You can retrieve the required names by calling ListAvailableManagedRuleGroups .

You cannot nest a ManagedRuleGroupStatement , for example for use inside a NotStatement or OrStatement . It can only be referenced as a top-level statement within a rule.

Note

You are charged additional fees when you use the WAF Bot Control managed rule group AWSManagedRulesBotControlRuleSet or the WAF Fraud Control account takeover prevention (ATP) managed rule group AWSManagedRulesATPRuleSet . For more information, see WAF Pricing .

VendorName -> (string)

The name of the managed rule group vendor. You use this, along with the rule group name, to identify the rule group.

Name -> (string)

The name of the managed rule group. You use this, along with the vendor name, to identify the rule group.

Version -> (string)

The version of the managed rule group to use. If you specify this, the version setting is fixed until you change it. If you don’t specify this, WAF uses the vendor’s default version, and then keeps the version at the vendor’s default when the vendor updates the managed rule group settings.

ExcludedRules -> (list)

Rules in the referenced rule group whose actions are set to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

(structure)

Specifies a single rule in a rule group whose action you want to override to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

Name -> (string)

The name of the rule whose action you want to override to Count .

( … recursive … )ManagedRuleGroupConfigs -> (list)

Additional information that’s used by a managed rule group. Many managed rule groups don’t require this.

Use the AWSManagedRulesATPRuleSet configuration object for the account takeover prevention managed rule group, to provide information such as the sign-in page of your application and the type of content to accept or reject from the client.

Use the AWSManagedRulesBotControlRuleSet configuration object to configure the protection level that you want the Bot Control rule group to use.

(structure)

Additional information that’s used by a managed rule group. Many managed rule groups don’t require this.

Use the AWSManagedRulesATPRuleSet configuration object for the account takeover prevention managed rule group, to provide information such as the sign-in page of your application and the type of content to accept or reject from the client.

Use the AWSManagedRulesBotControlRuleSet configuration object to configure the protection level that you want the Bot Control rule group to use.

For example specifications, see the examples section of CreateWebACL .

LoginPath -> (string)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet .

PayloadType -> (string)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet RequestInspection .

UsernameField -> (structure)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet RequestInspection .

Identifier -> (string)

The name of the username field. For example /form/username .

PasswordField -> (structure)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet RequestInspection .

Identifier -> (string)

The name of the password field. For example /form/password .

AWSManagedRulesBotControlRuleSet -> (structure)

Additional configuration for using the Bot Control managed rule group. Use this to specify the inspection level that you want to use. For information about using the Bot Control managed rule group, see WAF Bot Control rule group and WAF Bot Control in the WAF Developer Guide .

InspectionLevel -> (string)

The inspection level to use for the Bot Control rule group. The common level is the least expensive. The targeted level includes all common level rules and adds rules with more advanced inspection criteria. For details, see WAF Bot Control rule group in the WAF Developer Guide .

AWSManagedRulesATPRuleSet -> (structure)

Additional configuration for using the account takeover prevention (ATP) managed rule group, AWSManagedRulesATPRuleSet . Use this to provide login request information to the rule group. For web ACLs that protect CloudFront distributions, use this to also provide the information about how your distribution responds to login requests.

This configuration replaces the individual configuration fields in ManagedRuleGroupConfig and provides additional feature configuration.

For information about using the ATP managed rule group, see WAF Fraud Control account takeover prevention (ATP) rule group and WAF Fraud Control account takeover prevention (ATP) in the WAF Developer Guide .

LoginPath -> (string)

The path of the login endpoint for your application. For example, for the URL https://example.com/web/login , you would provide the path /web/login .

The rule group inspects only HTTP POST requests to your specified login endpoint.

RequestInspection -> (structure)

The criteria for inspecting login requests, used by the ATP rule group to validate credentials usage.

PayloadType -> (string)

The payload type for your login endpoint, either JSON or form encoded.

UsernameField -> (structure)

Details about your login page username field.

How you specify this depends on the payload type.

  • For JSON payloads, specify the field name in JSON pointer syntax. For information about the JSON Pointer syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer . For example, for the JSON payload { "login": { "username": "THE_USERNAME", "password": "THE_PASSWORD" } } , the username field specification is /login/username and the password field specification is /login/password .
  • For form encoded payload types, use the HTML form names. For example, for an HTML form with input elements named username1 and password1 , the username field specification is username1 and the password field specification is password1 .

Identifier -> (string)

The name of the username field. For example /form/username .

PasswordField -> (structure)

Details about your login page password field.

How you specify this depends on the payload type.

  • For JSON payloads, specify the field name in JSON pointer syntax. For information about the JSON Pointer syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer . For example, for the JSON payload { "login": { "username": "THE_USERNAME", "password": "THE_PASSWORD" } } , the username field specification is /login/username and the password field specification is /login/password .
  • For form encoded payload types, use the HTML form names. For example, for an HTML form with input elements named username1 and password1 , the username field specification is username1 and the password field specification is password1 .

Identifier -> (string)

The name of the password field. For example /form/password .

ResponseInspection -> (structure)

The criteria for inspecting responses to login requests, used by the ATP rule group to track login failure rates.

The ATP rule group evaluates the responses that your protected resources send back to client login attempts, keeping count of successful and failed attempts from each IP address and client session. Using this information, the rule group labels and mitigates requests from client sessions and IP addresses that submit too many failed login attempts in a short amount of time.

Note

Response inspection is available only in web ACLs that protect Amazon CloudFront distributions.

StatusCode -> (structure)

Configures inspection of the response status code.

SuccessCodes -> (list)

Status codes in the response that indicate a successful login attempt. To be counted as a successful login, the response status code must match one of these. Each code must be unique among the success and failure status codes.

JSON example: "SuccessCodes": [ 200, 201 ]

(integer)

FailureCodes -> (list)

Status codes in the response that indicate a failed login attempt. To be counted as a failed login, the response status code must match one of these. Each code must be unique among the success and failure status codes.

JSON example: "FailureCodes": [ 400, 404 ]

(integer)

Header -> (structure)

Configures inspection of the response header.

Name -> (string)

The name of the header to match against. The name must be an exact match, including case.

JSON example: "Name": [ "LoginResult" ]

SuccessValues -> (list)

Values in the response header with the specified name that indicate a successful login attempt. To be counted as a successful login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "SuccessValues": [ "LoginPassed", "Successful login" ]

(string)

FailureValues -> (list)

Values in the response header with the specified name that indicate a failed login attempt. To be counted as a failed login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "FailureValues": [ "LoginFailed", "Failed login" ]

(string)

BodyContains -> (structure)

Configures inspection of the response body. WAF can inspect the first 65,536 bytes (64 KB) of the response body.

SuccessStrings -> (list)

Strings in the body of the response that indicate a successful login attempt. To be counted as a successful login, the string can be anywhere in the body and must be an exact match, including case. Each string must be unique among the success and failure strings.

JSON example: "SuccessStrings": [ "Login successful", "Welcome to our site!" ]

(string)

FailureStrings -> (list)

Strings in the body of the response that indicate a failed login attempt. To be counted as a failed login, the string can be anywhere in the body and must be an exact match, including case. Each string must be unique among the success and failure strings.

JSON example: "FailureStrings": [ "Login failed" ]

(string)

Json -> (structure)

Configures inspection of the response JSON. WAF can inspect the first 65,536 bytes (64 KB) of the response JSON.

Identifier -> (string)

The identifier for the value to match against in the JSON. The identifier must be an exact match, including case.

JSON example: "Identifier": [ "/login/success" ]

SuccessValues -> (list)

Values for the specified identifier in the response JSON that indicate a successful login attempt. To be counted as a successful login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "SuccessValues": [ "True", "Succeeded" ]

(string)

FailureValues -> (list)

Values for the specified identifier in the response JSON that indicate a failed login attempt. To be counted as a failed login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "FailureValues": [ "False", "Failed" ]

(string)

RuleActionOverrides -> (list)

Action settings to use in the place of the rule actions that are configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

(structure)

Action setting to use in the place of a rule action that is configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

Name -> (string)

The name of the rule to override.

ActionToUse -> (structure)

The override action to use, in place of the configured action of the rule in the rule group.

Block -> (structure)

Instructs WAF to block the web request.

CustomResponse -> (structure)

Defines a custom response for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

ResponseCode -> (integer)

The HTTP status code to return to the client.

For a list of status codes that you can use in your custom responses, see Supported status codes for custom response in the WAF Developer Guide .

CustomResponseBodyKey -> (string)

References the response body that you want WAF to return to the web request client. You can define a custom response for a rule action or a default web ACL action that is set to block. To do this, you first define the response body key and value in the CustomResponseBodies setting for the WebACL or RuleGroup where you want to use it. Then, in the rule action or web ACL default action BlockAction setting, you reference the response body using this key.

ResponseHeaders -> (list)

The HTTP headers to use in the response. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Allow -> (structure)

Instructs WAF to allow the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Count -> (structure)

Instructs WAF to count the web request and then continue evaluating the request using the remaining rules in the web ACL.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Captcha -> (structure)

Instructs WAF to run a CAPTCHA check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the CAPTCHA inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Challenge -> (structure)

Instructs WAF to run a Challenge check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the challenge inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

LabelMatchStatement -> (structure)

A rule statement to match against labels that have been added to the web request by rules that have already run in the web ACL.

The label match statement provides the label or namespace string to search for. The label string can represent a part or all of the fully qualified label name that had been added to the web request. Fully qualified labels have a prefix, optional namespaces, and label name. The prefix identifies the rule group or web ACL context of the rule that added the label. If you do not provide the fully qualified name in your label match string, WAF performs the search for labels that were added in the same context as the label match statement.

Scope -> (string)

Specify whether you want to match using the label name or just the namespace.

Key -> (string)

The string to match against. The setting you provide for this depends on the match statement’s Scope setting:

  • If the Scope indicates LABEL , then this specification must include the name and can include any number of preceding namespace specifications and prefix up to providing the fully qualified label name.
  • If the Scope indicates NAMESPACE , then this specification can include any number of contiguous namespace strings, and can include the entire label namespace prefix from the rule group or web ACL where the label originates.

Labels are case sensitive and components of a label must be separated by colon, for example NS1:NS2:name .

RegexMatchStatement -> (structure)

A rule statement used to search web request components for a match against a single regular expression.

RegexString -> (string)

The string representing the regular expression.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

This is required if you specify a forwarded IP in the rule’s aggregate key settings.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

CustomKeys -> (list)

Specifies the aggregate keys to use in a rate-base rule.

(structure)

Specifies a single custom aggregate key for a rate-base rule.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.

Header -> (structure)

Use the value of a header in the request as an aggregate key. Each distinct value in the header contributes to the aggregation instance. If you use a single header as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the header to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

Cookie -> (structure)

Use the value of a cookie in the request as an aggregate key. Each distinct value in the cookie contributes to the aggregation instance. If you use a single cookie as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the cookie to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

QueryArgument -> (structure)

Use the specified query argument as an aggregate key. Each distinct value for the named query argument contributes to the aggregation instance. If you use a single query argument as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the query argument to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

QueryString -> (structure)

Use the request’s query string as an aggregate key. Each distinct string contributes to the aggregation instance. If you use just the query string as your custom key, then each string fully defines an aggregation instance.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

HTTPMethod -> (structure)

Use the request’s HTTP method as an aggregate key. Each distinct HTTP method contributes to the aggregation instance. If you use just the HTTP method as your custom key, then each method fully defines an aggregation instance.

ForwardedIP -> (structure)

Use the first IP address in an HTTP header as an aggregate key. Each distinct forwarded IP address contributes to the aggregation instance.

When you specify an IP or forwarded IP in the custom key settings, you must also specify at least one other key to use. You can aggregate on only the forwarded IP address by specifying FORWARDED_IP in your rate-based statement’s AggregateKeyType .

With this option, you must specify the header to use in the rate-based rule’s ForwardedIPConfig property.

IP -> (structure)

Use the request’s originating IP address as an aggregate key. Each distinct IP address contributes to the aggregation instance.

When you specify an IP or forwarded IP in the custom key settings, you must also specify at least one other key to use. You can aggregate on only the IP address by specifying IP in your rate-based statement’s AggregateKeyType .

LabelNamespace -> (structure)

Use the specified label namespace as an aggregate key. Each distinct fully qualified label name that has the specified label namespace contributes to the aggregation instance. If you use just one label namespace as your custom key, then each label name fully defines an aggregation instance.

This uses only labels that have been added to the request by rules that are evaluated before this rate-based rule in the web ACL.

For information about label namespaces and names, see Label syntax and naming requirements in the WAF Developer Guide .

Namespace -> (string)

The namespace to use for aggregation.

AndStatement -> (structure)

A logical rule statement used to combine other rule statements with AND logic. You provide more than one Statement within the AndStatement .

Statements -> (list)

The statements to combine with AND logic. You can use any statements that can be nested.

(structure)

The processing guidance for a Rule , used by WAF to determine whether a web request matches the rule.

For example specifications, see the examples section of CreateWebACL .

ByteMatchStatement -> (structure)

A rule statement that defines a string match search for WAF to apply to web requests. The byte match statement provides the bytes to search for, the location in requests that you want WAF to search, and other settings. The bytes to search for are typically a string that corresponds with ASCII characters. In the WAF console and the developer guide, this is called a string match statement.

SearchString -> (blob)

A string value that you want WAF to search for. WAF searches only in the part of web requests that you designate for inspection in FieldToMatch . The maximum length of the value is 200 bytes.

Valid values depend on the component that you specify for inspection in FieldToMatch :

  • Method : The HTTP method that you want WAF to search for. This indicates the type of operation specified in the request.
  • UriPath : The value that you want WAF to search for in the URI path, for example, /images/daily-ad.jpg .

If SearchString includes alphabetic characters A-Z and a-z, note that the value is case sensitive.

If you’re using the WAF API

Specify a base64-encoded version of the value. The maximum length of the value before you base64-encode it is 200 bytes.

For example, suppose the value of Type is HEADER and the value of Data is User-Agent . If you want to search the User-Agent header for the value BadBot , you base64-encode BadBot using MIME base64-encoding and include the resulting value, QmFkQm90 , in the value of SearchString .

If you’re using the CLI or one of the Amazon Web Services SDKs

The value that you want WAF to search for. The SDK automatically base64 encodes the value.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

PositionalConstraint -> (string)

The area within the portion of the web request that you want WAF to search for SearchString . Valid values include the following:

CONTAINS

The specified part of the web request must include the value of SearchString , but the location doesn’t matter.

CONTAINS_WORD

The specified part of the web request must include the value of SearchString , and SearchString must contain only alphanumeric characters or underscore (A-Z, a-z, 0-9, or _). In addition, SearchString must be a word, which means that both of the following are true:

  • SearchString is at the beginning of the specified part of the web request or is preceded by a character other than an alphanumeric character or underscore (_). Examples include the value of a header and ;BadBot .
  • SearchString is at the end of the specified part of the web request or is followed by a character other than an alphanumeric character or underscore (_), for example, BadBot; and -BadBot; .
EXACTLY

The value of the specified part of the web request must exactly match the value of SearchString .

STARTS_WITH

The value of SearchString must appear at the beginning of the specified part of the web request.

ENDS_WITH

The value of SearchString must appear at the end of the specified part of the web request.

SqliMatchStatement -> (structure)

A rule statement that inspects for malicious SQL code. Attackers insert malicious SQL code into web requests to do things like modify your database or extract data from it.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SensitivityLevel -> (string)

The sensitivity that you want WAF to use to inspect for SQL injection attacks.

HIGH detects more attacks, but might generate more false positives, especially if your web requests frequently contain unusual strings. For information about identifying and mitigating false positives, see Testing and tuning in the WAF Developer Guide .

LOW is generally a better choice for resources that already have other protections against SQL injection attacks or that have a low tolerance for false positives.

Default: LOW

XssMatchStatement -> (structure)

A rule statement that inspects for cross-site scripting (XSS) attacks. In XSS attacks, the attacker uses vulnerabilities in a benign website as a vehicle to inject malicious client-site scripts into other legitimate web browsers.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SizeConstraintStatement -> (structure)

A rule statement that compares a number of bytes against the size of a request component, using a comparison operator, such as greater than (>) or less than (<). For example, you can use a size constraint statement to look for query strings that are longer than 100 bytes.

If you configure WAF to inspect the request body, WAF inspects only the number of bytes of the body up to the limit for the web ACL. By default, for regional web ACLs, this limit is 8 KB (8,192 kilobytes) and for CloudFront web ACLs, this limit is 16 KB (16,384 kilobytes). For CloudFront web ACLs, you can increase the limit in the web ACL AssociationConfig , for additional fees. If you know that the request body for your web requests should never exceed the inspection limit, you could use a size constraint statement to block requests that have a larger request body size.

If you choose URI for the value of Part of the request to filter on, the slash (/) in the URI counts as one character. For example, the URI /logo.jpg is nine characters long.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

ComparisonOperator -> (string)

The operator to use to compare the request part to the size setting.

Size -> (long)

The size, in byte, to compare to the request part, after any transformations.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

GeoMatchStatement -> (structure)

A rule statement that labels web requests by country and region and that matches against web requests based on country code. A geo match rule labels every request that it inspects regardless of whether it finds a match.

  • To manage requests only by country, you can use this statement by itself and specify the countries that you want to match against in the CountryCodes array.
  • Otherwise, configure your geo match rule with Count action so that it only labels requests. Then, add one or more label match rules to run after the geo match rule and configure them to match against the geographic labels and handle the requests as needed.

WAF labels requests using the alpha-2 country and region codes from the International Organization for Standardization (ISO) 3166 standard. WAF determines the codes using either the IP address in the web request origin or, if you specify it, the address in the geo match ForwardedIPConfig .

If you use the web request origin, the label formats are awswaf:clientip:geo:region:<ISO country code>-<ISO region code> and awswaf:clientip:geo:country:<ISO country code> .

If you use a forwarded IP address, the label formats are awswaf:forwardedip:geo:region:<ISO country code>-<ISO region code> and awswaf:forwardedip:geo:country:<ISO country code> .

For additional details, see Geographic match rule statement in the WAF Developer Guide .

CountryCodes -> (list)

An array of two-character country codes that you want to match against, for example, [ "US", "CN" ] , from the alpha-2 country ISO codes of the ISO 3166 international standard.

When you use a geo match statement just for the region and country labels that it adds to requests, you still have to supply a country code for the rule to evaluate. In this case, you configure the rule to only count matching requests, but it will still generate logging and count metrics for any matches. You can reduce the logging and metrics that the rule produces by specifying a country that’s unlikely to be a source of traffic to your site.

(string)

ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

RuleGroupReferenceStatement -> (structure)

A rule statement used to run the rules that are defined in a RuleGroup . To use this, create a rule group with your rules, then provide the ARN of the rule group in this statement.

You cannot nest a RuleGroupReferenceStatement , for example for use inside a NotStatement or OrStatement . You can only use a rule group reference statement at the top level inside a web ACL.

ARN -> (string)

The Amazon Resource Name (ARN) of the entity.

ExcludedRules -> (list)

Rules in the referenced rule group whose actions are set to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

(structure)

Specifies a single rule in a rule group whose action you want to override to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

Name -> (string)

The name of the rule whose action you want to override to Count .

RuleActionOverrides -> (list)

Action settings to use in the place of the rule actions that are configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

(structure)

Action setting to use in the place of a rule action that is configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

Name -> (string)

The name of the rule to override.

ActionToUse -> (structure)

The override action to use, in place of the configured action of the rule in the rule group.

Block -> (structure)

Instructs WAF to block the web request.

CustomResponse -> (structure)

Defines a custom response for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

ResponseCode -> (integer)

The HTTP status code to return to the client.

For a list of status codes that you can use in your custom responses, see Supported status codes for custom response in the WAF Developer Guide .

CustomResponseBodyKey -> (string)

References the response body that you want WAF to return to the web request client. You can define a custom response for a rule action or a default web ACL action that is set to block. To do this, you first define the response body key and value in the CustomResponseBodies setting for the WebACL or RuleGroup where you want to use it. Then, in the rule action or web ACL default action BlockAction setting, you reference the response body using this key.

ResponseHeaders -> (list)

The HTTP headers to use in the response. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Allow -> (structure)

Instructs WAF to allow the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Count -> (structure)

Instructs WAF to count the web request and then continue evaluating the request using the remaining rules in the web ACL.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Captcha -> (structure)

Instructs WAF to run a CAPTCHA check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the CAPTCHA inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Challenge -> (structure)

Instructs WAF to run a Challenge check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the challenge inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

IPSetReferenceStatement -> (structure)

A rule statement used to detect web requests coming from particular IP addresses or address ranges. To use this, create an IPSet that specifies the addresses you want to detect, then use the ARN of that set in this statement. To create an IP set, see CreateIPSet .

Each IP set rule statement references an IP set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the IPSet that this statement references.

IPSetForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Position -> (string)

The position in the header to search for the IP address. The header can contain IP addresses of the original client and also of proxies. For example, the header value could be 10.1.1.1, 127.0.0.0, 10.10.10.10 where the first IP address identifies the original client and the rest identify proxies that the request went through.

The options for this setting are the following:

  • FIRST - Inspect the first IP address in the list of IP addresses in the header. This is usually the client’s original IP.
  • LAST - Inspect the last IP address in the list of IP addresses in the header.
  • ANY - Inspect all IP addresses in the header for a match. If the header contains more than 10 IP addresses, WAF inspects the last 10.

RegexPatternSetReferenceStatement -> (structure)

A rule statement used to search web request components for matches with regular expressions. To use this, create a RegexPatternSet that specifies the expressions that you want to detect, then use the ARN of that set in this statement. A web request matches the pattern set rule statement if the request component matches any of the patterns in the set. To create a regex pattern set, see CreateRegexPatternSet .

Each regex pattern set rule statement references a regex pattern set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the RegexPatternSet that this statement references.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

RateBasedStatement -> (structure)

A rate-based rule counts incoming requests and rate limits requests when they are coming at too fast a rate. The rule categorizes requests according to your aggregation criteria, collects them into aggregation instances, and counts and rate limits the requests for each instance.

You can specify individual aggregation keys, like IP address or HTTP method. You can also specify aggregation key combinations, like IP address and HTTP method, or HTTP method, query argument, and cookie.

Each unique set of values for the aggregation keys that you specify is a separate aggregation instance, with the value from each key contributing to the aggregation instance definition.

For example, assume the rule evaluates web requests with the following IP address and HTTP method values:

  • IP address 10.1.1.1, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET
  • IP address 127.0.0.0, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET

The rule would create different aggregation instances according to your aggregation criteria, for example:

  • If the aggregation criteria is just the IP address, then each individual address is an aggregation instance, and WAF counts requests separately for each. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1: count 3
    • IP address 127.0.0.0: count 1
  • If the aggregation criteria is HTTP method, then each individual HTTP method is an aggregation instance. The aggregation instances and request counts for our example would be the following:
    • HTTP method POST: count 2
    • HTTP method GET: count 2
  • If the aggregation criteria is IP address and HTTP method, then each IP address and each HTTP method would contribute to the combined aggregation instance. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1, HTTP method POST: count 1
    • IP address 10.1.1.1, HTTP method GET: count 2
    • IP address 127.0.0.0, HTTP method POST: count 1

For any n-tuple of aggregation keys, each unique combination of values for the keys defines a separate aggregation instance, which WAF counts and rate-limits individually.

You can optionally nest another statement inside the rate-based statement, to narrow the scope of the rule so that it only counts and rate limits requests that match the nested statement. You can use this nested scope-down statement in conjunction with your aggregation key specifications or you can just count and rate limit all requests that match the scope-down statement, without additional aggregation. When you choose to just manage all requests that match a scope-down statement, the aggregation instance is singular for the rule.

You cannot nest a RateBasedStatement inside another statement, for example inside a NotStatement or OrStatement . You can define a RateBasedStatement inside a web ACL and inside a rule group.

For additional information about the options, see Rate limiting web requests using rate-based rules in the WAF Developer Guide .

If you only aggregate on the individual IP address or forwarded IP address, you can retrieve the list of IP addresses that WAF is currently rate limiting for a rule through the API call GetRateBasedStatementManagedKeys . This option is not available for other aggregation configurations.

WAF tracks and manages web requests separately for each instance of a rate-based rule that you use. For example, if you provide the same rate-based rule settings in two web ACLs, each of the two rule statements represents a separate instance of the rate-based rule and gets its own tracking and management by WAF. If you define a rate-based rule inside a rule group, and then use that rule group in multiple places, each use creates a separate instance of the rate-based rule that gets its own tracking and management by WAF.

Limit -> (long)

The limit on requests per 5-minute period for a single aggregation instance for the rate-based rule. If the rate-based statement includes a ScopeDownStatement , this limit is applied only to the requests that match the statement.

Examples:

  • If you aggregate on just the IP address, this is the limit on requests from any single IP address.
  • If you aggregate on the HTTP method and the query argument name “city”, then this is the limit on requests for any single method, city pair.

AggregateKeyType -> (string)

Setting that indicates how to aggregate the request counts.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.
  • CONSTANT - Count and limit the requests that match the rate-based rule’s scope-down statement. With this option, the counted requests aren’t further aggregated. The scope-down statement is the only specification used. When the count of all requests that satisfy the scope-down statement goes over the limit, WAF applies the rule action to all requests that satisfy the scope-down statement. With this option, you must configure the ScopeDownStatement property.
  • CUSTOM_KEYS - Aggregate the request counts using one or more web request components as the aggregate keys. With this option, you must specify the aggregate keys in the CustomKeys property. To aggregate on only the IP address or only the forwarded IP address, don’t use custom keys. Instead, set the aggregate key type to IP or FORWARDED_IP .
  • FORWARDED_IP - Aggregate the request counts on the first IP address in an HTTP header. With this option, you must specify the header to use in the ForwardedIPConfig property. To aggregate on a combination of the forwarded IP address with other aggregate keys, use CUSTOM_KEYS .
  • IP - Aggregate the request counts on the IP address from the web request origin. To aggregate on a combination of the IP address with other aggregate keys, use CUSTOM_KEYS .

( … recursive … )ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

This is required if you specify a forwarded IP in the rule’s aggregate key settings.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

CustomKeys -> (list)

Specifies the aggregate keys to use in a rate-base rule.

(structure)

Specifies a single custom aggregate key for a rate-base rule.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.

Header -> (structure)

Use the value of a header in the request as an aggregate key. Each distinct value in the header contributes to the aggregation instance. If you use a single header as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the header to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

Cookie -> (structure)

Use the value of a cookie in the request as an aggregate key. Each distinct value in the cookie contributes to the aggregation instance. If you use a single cookie as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the cookie to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

QueryArgument -> (structure)

Use the specified query argument as an aggregate key. Each distinct value for the named query argument contributes to the aggregation instance. If you use a single query argument as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the query argument to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

QueryString -> (structure)

Use the request’s query string as an aggregate key. Each distinct string contributes to the aggregation instance. If you use just the query string as your custom key, then each string fully defines an aggregation instance.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

HTTPMethod -> (structure)

Use the request’s HTTP method as an aggregate key. Each distinct HTTP method contributes to the aggregation instance. If you use just the HTTP method as your custom key, then each method fully defines an aggregation instance.

ForwardedIP -> (structure)

Use the first IP address in an HTTP header as an aggregate key. Each distinct forwarded IP address contributes to the aggregation instance.

When you specify an IP or forwarded IP in the custom key settings, you must also specify at least one other key to use. You can aggregate on only the forwarded IP address by specifying FORWARDED_IP in your rate-based statement’s AggregateKeyType .

With this option, you must specify the header to use in the rate-based rule’s ForwardedIPConfig property.

IP -> (structure)

Use the request’s originating IP address as an aggregate key. Each distinct IP address contributes to the aggregation instance.

When you specify an IP or forwarded IP in the custom key settings, you must also specify at least one other key to use. You can aggregate on only the IP address by specifying IP in your rate-based statement’s AggregateKeyType .

LabelNamespace -> (structure)

Use the specified label namespace as an aggregate key. Each distinct fully qualified label name that has the specified label namespace contributes to the aggregation instance. If you use just one label namespace as your custom key, then each label name fully defines an aggregation instance.

This uses only labels that have been added to the request by rules that are evaluated before this rate-based rule in the web ACL.

For information about label namespaces and names, see Label syntax and naming requirements in the WAF Developer Guide .

Namespace -> (string)

The namespace to use for aggregation.

AndStatement -> (structure)

A logical rule statement used to combine other rule statements with AND logic. You provide more than one Statement within the AndStatement .

Statements -> (list)

The statements to combine with AND logic. You can use any statements that can be nested.

( … recursive … )

OrStatement -> (structure)

A logical rule statement used to combine other rule statements with OR logic. You provide more than one Statement within the OrStatement .

Statements -> (list)

The statements to combine with OR logic. You can use any statements that can be nested.

( … recursive … )

NotStatement -> (structure)

A logical rule statement used to negate the results of another rule statement. You provide one Statement within the NotStatement .

( … recursive … )

ManagedRuleGroupStatement -> (structure)

A rule statement used to run the rules that are defined in a managed rule group. To use this, provide the vendor name and the name of the rule group in this statement. You can retrieve the required names by calling ListAvailableManagedRuleGroups .

You cannot nest a ManagedRuleGroupStatement , for example for use inside a NotStatement or OrStatement . It can only be referenced as a top-level statement within a rule.

Note

You are charged additional fees when you use the WAF Bot Control managed rule group AWSManagedRulesBotControlRuleSet or the WAF Fraud Control account takeover prevention (ATP) managed rule group AWSManagedRulesATPRuleSet . For more information, see WAF Pricing .

VendorName -> (string)

The name of the managed rule group vendor. You use this, along with the rule group name, to identify the rule group.

Name -> (string)

The name of the managed rule group. You use this, along with the vendor name, to identify the rule group.

Version -> (string)

The version of the managed rule group to use. If you specify this, the version setting is fixed until you change it. If you don’t specify this, WAF uses the vendor’s default version, and then keeps the version at the vendor’s default when the vendor updates the managed rule group settings.

ExcludedRules -> (list)

Rules in the referenced rule group whose actions are set to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

(structure)

Specifies a single rule in a rule group whose action you want to override to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

Name -> (string)

The name of the rule whose action you want to override to Count .

( … recursive … )ManagedRuleGroupConfigs -> (list)

Additional information that’s used by a managed rule group. Many managed rule groups don’t require this.

Use the AWSManagedRulesATPRuleSet configuration object for the account takeover prevention managed rule group, to provide information such as the sign-in page of your application and the type of content to accept or reject from the client.

Use the AWSManagedRulesBotControlRuleSet configuration object to configure the protection level that you want the Bot Control rule group to use.

(structure)

Additional information that’s used by a managed rule group. Many managed rule groups don’t require this.

Use the AWSManagedRulesATPRuleSet configuration object for the account takeover prevention managed rule group, to provide information such as the sign-in page of your application and the type of content to accept or reject from the client.

Use the AWSManagedRulesBotControlRuleSet configuration object to configure the protection level that you want the Bot Control rule group to use.

For example specifications, see the examples section of CreateWebACL .

LoginPath -> (string)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet .

PayloadType -> (string)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet RequestInspection .

UsernameField -> (structure)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet RequestInspection .

Identifier -> (string)

The name of the username field. For example /form/username .

PasswordField -> (structure)

Note

Instead of this setting, provide your configuration under AWSManagedRulesATPRuleSet RequestInspection .

Identifier -> (string)

The name of the password field. For example /form/password .

AWSManagedRulesBotControlRuleSet -> (structure)

Additional configuration for using the Bot Control managed rule group. Use this to specify the inspection level that you want to use. For information about using the Bot Control managed rule group, see WAF Bot Control rule group and WAF Bot Control in the WAF Developer Guide .

InspectionLevel -> (string)

The inspection level to use for the Bot Control rule group. The common level is the least expensive. The targeted level includes all common level rules and adds rules with more advanced inspection criteria. For details, see WAF Bot Control rule group in the WAF Developer Guide .

AWSManagedRulesATPRuleSet -> (structure)

Additional configuration for using the account takeover prevention (ATP) managed rule group, AWSManagedRulesATPRuleSet . Use this to provide login request information to the rule group. For web ACLs that protect CloudFront distributions, use this to also provide the information about how your distribution responds to login requests.

This configuration replaces the individual configuration fields in ManagedRuleGroupConfig and provides additional feature configuration.

For information about using the ATP managed rule group, see WAF Fraud Control account takeover prevention (ATP) rule group and WAF Fraud Control account takeover prevention (ATP) in the WAF Developer Guide .

LoginPath -> (string)

The path of the login endpoint for your application. For example, for the URL https://example.com/web/login , you would provide the path /web/login .

The rule group inspects only HTTP POST requests to your specified login endpoint.

RequestInspection -> (structure)

The criteria for inspecting login requests, used by the ATP rule group to validate credentials usage.

PayloadType -> (string)

The payload type for your login endpoint, either JSON or form encoded.

UsernameField -> (structure)

Details about your login page username field.

How you specify this depends on the payload type.

  • For JSON payloads, specify the field name in JSON pointer syntax. For information about the JSON Pointer syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer . For example, for the JSON payload { "login": { "username": "THE_USERNAME", "password": "THE_PASSWORD" } } , the username field specification is /login/username and the password field specification is /login/password .
  • For form encoded payload types, use the HTML form names. For example, for an HTML form with input elements named username1 and password1 , the username field specification is username1 and the password field specification is password1 .

Identifier -> (string)

The name of the username field. For example /form/username .

PasswordField -> (structure)

Details about your login page password field.

How you specify this depends on the payload type.

  • For JSON payloads, specify the field name in JSON pointer syntax. For information about the JSON Pointer syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer . For example, for the JSON payload { "login": { "username": "THE_USERNAME", "password": "THE_PASSWORD" } } , the username field specification is /login/username and the password field specification is /login/password .
  • For form encoded payload types, use the HTML form names. For example, for an HTML form with input elements named username1 and password1 , the username field specification is username1 and the password field specification is password1 .

Identifier -> (string)

The name of the password field. For example /form/password .

ResponseInspection -> (structure)

The criteria for inspecting responses to login requests, used by the ATP rule group to track login failure rates.

The ATP rule group evaluates the responses that your protected resources send back to client login attempts, keeping count of successful and failed attempts from each IP address and client session. Using this information, the rule group labels and mitigates requests from client sessions and IP addresses that submit too many failed login attempts in a short amount of time.

Note

Response inspection is available only in web ACLs that protect Amazon CloudFront distributions.

StatusCode -> (structure)

Configures inspection of the response status code.

SuccessCodes -> (list)

Status codes in the response that indicate a successful login attempt. To be counted as a successful login, the response status code must match one of these. Each code must be unique among the success and failure status codes.

JSON example: "SuccessCodes": [ 200, 201 ]

(integer)

FailureCodes -> (list)

Status codes in the response that indicate a failed login attempt. To be counted as a failed login, the response status code must match one of these. Each code must be unique among the success and failure status codes.

JSON example: "FailureCodes": [ 400, 404 ]

(integer)

Header -> (structure)

Configures inspection of the response header.

Name -> (string)

The name of the header to match against. The name must be an exact match, including case.

JSON example: "Name": [ "LoginResult" ]

SuccessValues -> (list)

Values in the response header with the specified name that indicate a successful login attempt. To be counted as a successful login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "SuccessValues": [ "LoginPassed", "Successful login" ]

(string)

FailureValues -> (list)

Values in the response header with the specified name that indicate a failed login attempt. To be counted as a failed login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "FailureValues": [ "LoginFailed", "Failed login" ]

(string)

BodyContains -> (structure)

Configures inspection of the response body. WAF can inspect the first 65,536 bytes (64 KB) of the response body.

SuccessStrings -> (list)

Strings in the body of the response that indicate a successful login attempt. To be counted as a successful login, the string can be anywhere in the body and must be an exact match, including case. Each string must be unique among the success and failure strings.

JSON example: "SuccessStrings": [ "Login successful", "Welcome to our site!" ]

(string)

FailureStrings -> (list)

Strings in the body of the response that indicate a failed login attempt. To be counted as a failed login, the string can be anywhere in the body and must be an exact match, including case. Each string must be unique among the success and failure strings.

JSON example: "FailureStrings": [ "Login failed" ]

(string)

Json -> (structure)

Configures inspection of the response JSON. WAF can inspect the first 65,536 bytes (64 KB) of the response JSON.

Identifier -> (string)

The identifier for the value to match against in the JSON. The identifier must be an exact match, including case.

JSON example: "Identifier": [ "/login/success" ]

SuccessValues -> (list)

Values for the specified identifier in the response JSON that indicate a successful login attempt. To be counted as a successful login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "SuccessValues": [ "True", "Succeeded" ]

(string)

FailureValues -> (list)

Values for the specified identifier in the response JSON that indicate a failed login attempt. To be counted as a failed login, the value must be an exact match, including case. Each value must be unique among the success and failure values.

JSON example: "FailureValues": [ "False", "Failed" ]

(string)

RuleActionOverrides -> (list)

Action settings to use in the place of the rule actions that are configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

(structure)

Action setting to use in the place of a rule action that is configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

Name -> (string)

The name of the rule to override.

ActionToUse -> (structure)

The override action to use, in place of the configured action of the rule in the rule group.

Block -> (structure)

Instructs WAF to block the web request.

CustomResponse -> (structure)

Defines a custom response for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

ResponseCode -> (integer)

The HTTP status code to return to the client.

For a list of status codes that you can use in your custom responses, see Supported status codes for custom response in the WAF Developer Guide .

CustomResponseBodyKey -> (string)

References the response body that you want WAF to return to the web request client. You can define a custom response for a rule action or a default web ACL action that is set to block. To do this, you first define the response body key and value in the CustomResponseBodies setting for the WebACL or RuleGroup where you want to use it. Then, in the rule action or web ACL default action BlockAction setting, you reference the response body using this key.

ResponseHeaders -> (list)

The HTTP headers to use in the response. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Allow -> (structure)

Instructs WAF to allow the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Count -> (structure)

Instructs WAF to count the web request and then continue evaluating the request using the remaining rules in the web ACL.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Captcha -> (structure)

Instructs WAF to run a CAPTCHA check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the CAPTCHA inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Challenge -> (structure)

Instructs WAF to run a Challenge check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the challenge inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

LabelMatchStatement -> (structure)

A rule statement to match against labels that have been added to the web request by rules that have already run in the web ACL.

The label match statement provides the label or namespace string to search for. The label string can represent a part or all of the fully qualified label name that had been added to the web request. Fully qualified labels have a prefix, optional namespaces, and label name. The prefix identifies the rule group or web ACL context of the rule that added the label. If you do not provide the fully qualified name in your label match string, WAF performs the search for labels that were added in the same context as the label match statement.

Scope -> (string)

Specify whether you want to match using the label name or just the namespace.

Key -> (string)

The string to match against. The setting you provide for this depends on the match statement’s Scope setting:

  • If the Scope indicates LABEL , then this specification must include the name and can include any number of preceding namespace specifications and prefix up to providing the fully qualified label name.
  • If the Scope indicates NAMESPACE , then this specification can include any number of contiguous namespace strings, and can include the entire label namespace prefix from the rule group or web ACL where the label originates.

Labels are case sensitive and components of a label must be separated by colon, for example NS1:NS2:name .

RegexMatchStatement -> (structure)

A rule statement used to search web request components for a match against a single regular expression.

RegexString -> (string)

The string representing the regular expression.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

OrStatement -> (structure)

A logical rule statement used to combine other rule statements with OR logic. You provide more than one Statement within the OrStatement .

Statements -> (list)

The statements to combine with OR logic. You can use any statements that can be nested.

(structure)

The processing guidance for a Rule , used by WAF to determine whether a web request matches the rule.

For example specifications, see the examples section of CreateWebACL .

ByteMatchStatement -> (structure)

A rule statement that defines a string match search for WAF to apply to web requests. The byte match statement provides the bytes to search for, the location in requests that you want WAF to search, and other settings. The bytes to search for are typically a string that corresponds with ASCII characters. In the WAF console and the developer guide, this is called a string match statement.

SearchString -> (blob)

A string value that you want WAF to search for. WAF searches only in the part of web requests that you designate for inspection in FieldToMatch . The maximum length of the value is 200 bytes.

Valid values depend on the component that you specify for inspection in FieldToMatch :

  • Method : The HTTP method that you want WAF to search for. This indicates the type of operation specified in the request.
  • UriPath : The value that you want WAF to search for in the URI path, for example, /images/daily-ad.jpg .

If SearchString includes alphabetic characters A-Z and a-z, note that the value is case sensitive.

If you’re using the WAF API

Specify a base64-encoded version of the value. The maximum length of the value before you base64-encode it is 200 bytes.

For example, suppose the value of Type is HEADER and the value of Data is User-Agent . If you want to search the User-Agent header for the value BadBot , you base64-encode BadBot using MIME base64-encoding and include the resulting value, QmFkQm90 , in the value of SearchString .

If you’re using the CLI or one of the Amazon Web Services SDKs

The value that you want WAF to search for. The SDK automatically base64 encodes the value.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

PositionalConstraint -> (string)

The area within the portion of the web request that you want WAF to search for SearchString . Valid values include the following:

CONTAINS

The specified part of the web request must include the value of SearchString , but the location doesn’t matter.

CONTAINS_WORD

The specified part of the web request must include the value of SearchString , and SearchString must contain only alphanumeric characters or underscore (A-Z, a-z, 0-9, or _). In addition, SearchString must be a word, which means that both of the following are true:

  • SearchString is at the beginning of the specified part of the web request or is preceded by a character other than an alphanumeric character or underscore (_). Examples include the value of a header and ;BadBot .
  • SearchString is at the end of the specified part of the web request or is followed by a character other than an alphanumeric character or underscore (_), for example, BadBot; and -BadBot; .
EXACTLY

The value of the specified part of the web request must exactly match the value of SearchString .

STARTS_WITH

The value of SearchString must appear at the beginning of the specified part of the web request.

ENDS_WITH

The value of SearchString must appear at the end of the specified part of the web request.

SqliMatchStatement -> (structure)

A rule statement that inspects for malicious SQL code. Attackers insert malicious SQL code into web requests to do things like modify your database or extract data from it.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SensitivityLevel -> (string)

The sensitivity that you want WAF to use to inspect for SQL injection attacks.

HIGH detects more attacks, but might generate more false positives, especially if your web requests frequently contain unusual strings. For information about identifying and mitigating false positives, see Testing and tuning in the WAF Developer Guide .

LOW is generally a better choice for resources that already have other protections against SQL injection attacks or that have a low tolerance for false positives.

Default: LOW

XssMatchStatement -> (structure)

A rule statement that inspects for cross-site scripting (XSS) attacks. In XSS attacks, the attacker uses vulnerabilities in a benign website as a vehicle to inject malicious client-site scripts into other legitimate web browsers.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

SizeConstraintStatement -> (structure)

A rule statement that compares a number of bytes against the size of a request component, using a comparison operator, such as greater than (>) or less than (<). For example, you can use a size constraint statement to look for query strings that are longer than 100 bytes.

If you configure WAF to inspect the request body, WAF inspects only the number of bytes of the body up to the limit for the web ACL. By default, for regional web ACLs, this limit is 8 KB (8,192 kilobytes) and for CloudFront web ACLs, this limit is 16 KB (16,384 kilobytes). For CloudFront web ACLs, you can increase the limit in the web ACL AssociationConfig , for additional fees. If you know that the request body for your web requests should never exceed the inspection limit, you could use a size constraint statement to block requests that have a larger request body size.

If you choose URI for the value of Part of the request to filter on, the slash (/) in the URI counts as one character. For example, the URI /logo.jpg is nine characters long.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

ComparisonOperator -> (string)

The operator to use to compare the request part to the size setting.

Size -> (long)

The size, in byte, to compare to the request part, after any transformations.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

GeoMatchStatement -> (structure)

A rule statement that labels web requests by country and region and that matches against web requests based on country code. A geo match rule labels every request that it inspects regardless of whether it finds a match.

  • To manage requests only by country, you can use this statement by itself and specify the countries that you want to match against in the CountryCodes array.
  • Otherwise, configure your geo match rule with Count action so that it only labels requests. Then, add one or more label match rules to run after the geo match rule and configure them to match against the geographic labels and handle the requests as needed.

WAF labels requests using the alpha-2 country and region codes from the International Organization for Standardization (ISO) 3166 standard. WAF determines the codes using either the IP address in the web request origin or, if you specify it, the address in the geo match ForwardedIPConfig .

If you use the web request origin, the label formats are awswaf:clientip:geo:region:<ISO country code>-<ISO region code> and awswaf:clientip:geo:country:<ISO country code> .

If you use a forwarded IP address, the label formats are awswaf:forwardedip:geo:region:<ISO country code>-<ISO region code> and awswaf:forwardedip:geo:country:<ISO country code> .

For additional details, see Geographic match rule statement in the WAF Developer Guide .

CountryCodes -> (list)

An array of two-character country codes that you want to match against, for example, [ "US", "CN" ] , from the alpha-2 country ISO codes of the ISO 3166 international standard.

When you use a geo match statement just for the region and country labels that it adds to requests, you still have to supply a country code for the rule to evaluate. In this case, you configure the rule to only count matching requests, but it will still generate logging and count metrics for any matches. You can reduce the logging and metrics that the rule produces by specifying a country that’s unlikely to be a source of traffic to your site.

(string)

ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

RuleGroupReferenceStatement -> (structure)

A rule statement used to run the rules that are defined in a RuleGroup . To use this, create a rule group with your rules, then provide the ARN of the rule group in this statement.

You cannot nest a RuleGroupReferenceStatement , for example for use inside a NotStatement or OrStatement . You can only use a rule group reference statement at the top level inside a web ACL.

ARN -> (string)

The Amazon Resource Name (ARN) of the entity.

ExcludedRules -> (list)

Rules in the referenced rule group whose actions are set to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

(structure)

Specifies a single rule in a rule group whose action you want to override to Count .

Note

Instead of this option, use RuleActionOverrides . It accepts any valid action setting, including Count .

Name -> (string)

The name of the rule whose action you want to override to Count .

RuleActionOverrides -> (list)

Action settings to use in the place of the rule actions that are configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

(structure)

Action setting to use in the place of a rule action that is configured inside the rule group. You specify one override for each rule whose action you want to change.

You can use overrides for testing, for example you can override all of rule actions to Count and then monitor the resulting count metrics to understand how the rule group would handle your web traffic. You can also permanently override some or all actions, to modify how the rule group manages your web traffic.

Name -> (string)

The name of the rule to override.

ActionToUse -> (structure)

The override action to use, in place of the configured action of the rule in the rule group.

Block -> (structure)

Instructs WAF to block the web request.

CustomResponse -> (structure)

Defines a custom response for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

ResponseCode -> (integer)

The HTTP status code to return to the client.

For a list of status codes that you can use in your custom responses, see Supported status codes for custom response in the WAF Developer Guide .

CustomResponseBodyKey -> (string)

References the response body that you want WAF to return to the web request client. You can define a custom response for a rule action or a default web ACL action that is set to block. To do this, you first define the response body key and value in the CustomResponseBodies setting for the WebACL or RuleGroup where you want to use it. Then, in the rule action or web ACL default action BlockAction setting, you reference the response body using this key.

ResponseHeaders -> (list)

The HTTP headers to use in the response. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Allow -> (structure)

Instructs WAF to allow the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Count -> (structure)

Instructs WAF to count the web request and then continue evaluating the request using the remaining rules in the web ACL.

CustomRequestHandling -> (structure)

Defines custom handling for the web request.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Captcha -> (structure)

Instructs WAF to run a CAPTCHA check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the CAPTCHA inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

Challenge -> (structure)

Instructs WAF to run a Challenge check against the web request.

CustomRequestHandling -> (structure)

Defines custom handling for the web request, used when the challenge inspection determines that the request’s token is valid and unexpired.

For information about customizing web requests and responses, see Customizing web requests and responses in WAF in the WAF Developer Guide .

InsertHeaders -> (list)

The HTTP headers to insert into the request. Duplicate header names are not allowed.

For information about the limits on count and size for custom request and response settings, see WAF quotas in the WAF Developer Guide .

(structure)

A custom header for custom request and response handling. This is used in CustomResponse and CustomRequestHandling .

Name -> (string)

The name of the custom header.

For custom request header insertion, when WAF inserts the header into the request, it prefixes this name x-amzn-waf- , to avoid confusion with the headers that are already in the request. For example, for the header name sample , WAF inserts the header x-amzn-waf-sample .

Value -> (string)

The value of the custom header.

IPSetReferenceStatement -> (structure)

A rule statement used to detect web requests coming from particular IP addresses or address ranges. To use this, create an IPSet that specifies the addresses you want to detect, then use the ARN of that set in this statement. To create an IP set, see CreateIPSet .

Each IP set rule statement references an IP set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the IPSet that this statement references.

IPSetForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Position -> (string)

The position in the header to search for the IP address. The header can contain IP addresses of the original client and also of proxies. For example, the header value could be 10.1.1.1, 127.0.0.0, 10.10.10.10 where the first IP address identifies the original client and the rest identify proxies that the request went through.

The options for this setting are the following:

  • FIRST - Inspect the first IP address in the list of IP addresses in the header. This is usually the client’s original IP.
  • LAST - Inspect the last IP address in the list of IP addresses in the header.
  • ANY - Inspect all IP addresses in the header for a match. If the header contains more than 10 IP addresses, WAF inspects the last 10.

RegexPatternSetReferenceStatement -> (structure)

A rule statement used to search web request components for matches with regular expressions. To use this, create a RegexPatternSet that specifies the expressions that you want to detect, then use the ARN of that set in this statement. A web request matches the pattern set rule statement if the request component matches any of the patterns in the set. To create a regex pattern set, see CreateRegexPatternSet .

Each regex pattern set rule statement references a regex pattern set. You create and maintain the set independent of your rules. This allows you to use the single set in multiple rules. When you update the referenced set, WAF automatically updates all rules that reference it.

ARN -> (string)

The Amazon Resource Name (ARN) of the RegexPatternSet that this statement references.

FieldToMatch -> (structure)

The part of the web request that you want WAF to inspect.

SingleHeader -> (structure)

Inspect a single header. Provide the name of the header to inspect, for example, User-Agent or Referer . This setting isn’t case sensitive.

Example JSON: "SingleHeader": { "Name": "haystack" }

Alternately, you can filter and inspect all headers with the Headers FieldToMatch setting.

Name -> (string)

The name of the query header to inspect.

SingleQueryArgument -> (structure)

Inspect a single query argument. Provide the name of the query argument to inspect, such as UserName or SalesRegion . The name can be up to 30 characters long and isn’t case sensitive.

Example JSON: "SingleQueryArgument": { "Name": "myArgument" }

Name -> (string)

The name of the query argument to inspect.

AllQueryArguments -> (structure)

Inspect all query arguments.

UriPath -> (structure)

Inspect the request URI path. This is the part of the web request that identifies a resource, for example, /images/daily-ad.jpg .

QueryString -> (structure)

Inspect the query string. This is the part of a URL that appears after a ? character, if any.

Body -> (structure)

Inspect the request body as plain text. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the Body object configuration.

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Method -> (structure)

Inspect the HTTP method. The method indicates the type of operation that the request is asking the origin to perform.

JsonBody -> (structure)

Inspect the request body as JSON. The request body immediately follows the request headers. This is the part of a request that contains any additional data that you want to send to your web server as the HTTP request body, such as data from a form.

A limited amount of the request body is forwarded to WAF for inspection by the underlying host service. For regional resources, the limit is 8 KB (8,192 kilobytes) and for CloudFront distributions, the limit is 16 KB (16,384 kilobytes). For CloudFront distributions, you can increase the limit in the web ACL’s AssociationConfig , for additional processing fees.

For information about how to handle oversized request bodies, see the JsonBody object configuration.

MatchPattern -> (structure)

The patterns to look for in the JSON body. WAF inspects the results of these pattern matches against the rule inspection criteria.

All -> (structure)

Match all of the elements. See also MatchScope in JsonBody .

You must specify either this setting or the IncludedPaths setting, but not both.

IncludedPaths -> (list)

Match only the specified include paths. See also MatchScope in JsonBody .

Provide the include paths using JSON Pointer syntax. For example, "IncludedPaths": ["/dogs/0/name", "/dogs/1/name"] . For information about this syntax, see the Internet Engineering Task Force (IETF) documentation JavaScript Object Notation (JSON) Pointer .

You must specify either this setting or the All setting, but not both.

Note

Don’t use this option to include all paths. Instead, use the All setting.

(string)

MatchScope -> (string)

The parts of the JSON to match against using the MatchPattern . If you specify All , WAF matches against keys and values.

InvalidFallbackBehavior -> (string)

What WAF should do if it fails to completely parse the JSON body. The options are the following:

  • EVALUATE_AS_STRING - Inspect the body as plain text. WAF applies the text transformations and inspection criteria that you defined for the JSON inspection to the body text string.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

If you don’t provide this setting, WAF parses and evaluates the content only up to the first parsing failure that it encounters.

WAF does its best to parse the entire JSON body, but might be forced to stop for reasons such as invalid characters, duplicate keys, truncation, and any content whose root node isn’t an object or an array.

WAF parses the JSON in the following examples as two valid key, value pairs:

  • Missing comma: {"key1":"value1""key2":"value2"}
  • Missing colon: {"key1":"value1","key2""value2"}
  • Extra colons: {"key1"::"value1","key2""value2"}

OversizeHandling -> (string)

What WAF should do if the body is larger than WAF can inspect. WAF does not support inspecting the entire contents of the web request body if the body exceeds the limit for the resource type. If the body is larger than the limit, the underlying host service only forwards the contents that are below the limit to WAF for inspection.

The default limit is 8 KB (8,192 kilobytes) for regional resources and 16 KB (16,384 kilobytes) for CloudFront distributions. For CloudFront distributions, you can increase the limit in the web ACL AssociationConfig , for additional processing fees.

The options for oversize handling are the following:

  • CONTINUE - Inspect the body normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

You can combine the MATCH or NO_MATCH settings for oversize handling with your rule and web ACL action settings, so that you block any request whose body is over the limit.

Default: CONTINUE

Headers -> (structure)

Inspect the request headers. You must configure scope and pattern matching filters in the Headers object, to define the set of headers to and the parts of the headers that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s headers and only the first 200 headers are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize header content in the Headers object. WAF applies the pattern matching filters to the headers that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of headers to inspect in a web request.

You must specify exactly one setting: either All , IncludedHeaders , or ExcludedHeaders .

Example JSON: "MatchPattern": { "ExcludedHeaders": {"KeyToExclude1", "KeyToExclude2"} }

All -> (structure)

Inspect all headers.

IncludedHeaders -> (list)

Inspect only the headers that have a key that matches one of the strings specified here.

(string)

ExcludedHeaders -> (list)

Inspect only the headers whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the headers to match with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the headers of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request headers when they exceed 8 KB (8192 bytes) or 200 total headers. The underlying host service forwards a maximum of 200 headers and at most 8 KB of header contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the headers normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

Cookies -> (structure)

Inspect the request cookies. You must configure scope and pattern matching filters in the Cookies object, to define the set of cookies and the parts of the cookies that WAF inspects.

Only the first 8 KB (8192 bytes) of a request’s cookies and only the first 200 cookies are forwarded to WAF for inspection by the underlying host service. You must configure how to handle any oversize cookie content in the Cookies object. WAF applies the pattern matching filters to the cookies that it receives from the underlying host service.

MatchPattern -> (structure)

The filter to use to identify the subset of cookies to inspect in a web request.

You must specify exactly one setting: either All , IncludedCookies , or ExcludedCookies .

Example JSON: "MatchPattern": { "IncludedCookies": {"KeyToInclude1", "KeyToInclude2", "KeyToInclude3"} }

All -> (structure)

Inspect all cookies.

IncludedCookies -> (list)

Inspect only the cookies that have a key that matches one of the strings specified here.

(string)

ExcludedCookies -> (list)

Inspect only the cookies whose keys don’t match any of the strings specified here.

(string)

MatchScope -> (string)

The parts of the cookies to inspect with the rule inspection criteria. If you specify All , WAF inspects both keys and values.

OversizeHandling -> (string)

What WAF should do if the cookies of the request are larger than WAF can inspect. WAF does not support inspecting the entire contents of request cookies when they exceed 8 KB (8192 bytes) or 200 total cookies. The underlying host service forwards a maximum of 200 cookies and at most 8 KB of cookie contents to WAF.

The options for oversize handling are the following:

  • CONTINUE - Inspect the cookies normally, according to the rule inspection criteria.
  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: / (
  • Replace the following characters with a space: , ;
  • Replace multiple spaces with one space
  • Convert uppercase letters (A-Z) to lowercase (a-z)
COMPRESS_WHITE_SPACE - Replace these characters with a space character (decimal 32):
  • \f , formfeed, decimal 12
  • \t , tab, decimal 9
  • \n , newline, decimal 10
  • \r , carriage return, decimal 13
  • \v , vertical tab, decimal 11
  • Non-breaking space, decimal 160

COMPRESS_WHITE_SPACE also replaces multiple spaces with one space.

CSS_DECODE - Decode characters that were encoded using CSS 2.x escape rules syndata.html#characters . This function uses up to two bytes in the decoding process, so it can help to uncover ASCII characters that were encoded using CSS encoding that wouldn’t typically be encoded. It’s also useful in countering evasion, which is a combination of a backslash and non-hexadecimal characters. For example, ja\vascript for javascript.

ESCAPE_SEQ_DECODE - Decode the following ANSI C escape sequences: \a , \b , \f , \n , \r , \t , \v , \\ , \? , \' , \" , \xHH (hexadecimal), \0OOO (octal). Encodings that aren’t valid remain in the output.

HEX_DECODE - Decode a string of hexadecimal characters into a binary.

HTML_ENTITY_DECODE - Replace HTML-encoded characters with unencoded characters. HTML_ENTITY_DECODE performs these operations:

  • Replaces (ampersand)quot; with "
  • Replaces (ampersand)nbsp; with a non-breaking space, decimal 160
  • Replaces (ampersand)lt; with a “less than” symbol
  • Replaces (ampersand)gt; with >
  • Replaces characters that are represented in hexadecimal format, (ampersand)#xhhhh; , with the corresponding characters
  • Replaces characters that are represented in decimal format, (ampersand)#nnnn; , with the corresponding characters

JS_DECODE - Decode JavaScript escape sequences. If a \ u HHHH code is in the full-width ASCII code range of FF01-FF5E , then the higher byte is used to detect and adjust the lower byte. If not, only the lower byte is used and the higher byte is zeroed, causing a possible loss of information.

LOWERCASE - Convert uppercase letters (A-Z) to lowercase (a-z).

MD5 - Calculate an MD5 hash from the data in the input. The computed hash is in a raw binary form.

NONE - Specify NONE if you don’t want any text transformations.

NORMALIZE_PATH - Remove multiple slashes, directory self-references, and directory back-references that are not at the beginning of the input from an input string.

NORMALIZE_PATH_WIN - This is the same as NORMALIZE_PATH , but first converts backslash characters to forward slashes.

REMOVE_NULLS - Remove all NULL bytes from the input.

REPLACE_COMMENTS - Replace each occurrence of a C-style comment (/* ... */ ) with a single space. Multiple consecutive occurrences are not compressed. Unterminated comments are also replaced with a space (ASCII 0x20). However, a standalone termination of a comment (*/ ) is not acted upon.

REPLACE_NULLS - Replace NULL bytes in the input with space characters (ASCII 0x20 ).

SQL_HEX_DECODE - Decode SQL hex data. Example (0x414243 ) will be decoded to (ABC ).

URL_DECODE - Decode a URL-encoded value.

URL_DECODE_UNI - Like URL_DECODE , but with support for Microsoft-specific %u encoding. If the code is in the full-width ASCII code range of FF01-FF5E , the higher byte is used to detect and adjust the lower byte. Otherwise, only the lower byte is used and the higher byte is zeroed.

UTF8_TO_UNICODE - Convert all UTF-8 character sequences to Unicode. This helps input normalization, and minimizing false-positives and false-negatives for non-English languages.

RateBasedStatement -> (structure)

A rate-based rule counts incoming requests and rate limits requests when they are coming at too fast a rate. The rule categorizes requests according to your aggregation criteria, collects them into aggregation instances, and counts and rate limits the requests for each instance.

You can specify individual aggregation keys, like IP address or HTTP method. You can also specify aggregation key combinations, like IP address and HTTP method, or HTTP method, query argument, and cookie.

Each unique set of values for the aggregation keys that you specify is a separate aggregation instance, with the value from each key contributing to the aggregation instance definition.

For example, assume the rule evaluates web requests with the following IP address and HTTP method values:

  • IP address 10.1.1.1, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET
  • IP address 127.0.0.0, HTTP method POST
  • IP address 10.1.1.1, HTTP method GET

The rule would create different aggregation instances according to your aggregation criteria, for example:

  • If the aggregation criteria is just the IP address, then each individual address is an aggregation instance, and WAF counts requests separately for each. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1: count 3
    • IP address 127.0.0.0: count 1
  • If the aggregation criteria is HTTP method, then each individual HTTP method is an aggregation instance. The aggregation instances and request counts for our example would be the following:
    • HTTP method POST: count 2
    • HTTP method GET: count 2
  • If the aggregation criteria is IP address and HTTP method, then each IP address and each HTTP method would contribute to the combined aggregation instance. The aggregation instances and request counts for our example would be the following:
    • IP address 10.1.1.1, HTTP method POST: count 1
    • IP address 10.1.1.1, HTTP method GET: count 2
    • IP address 127.0.0.0, HTTP method POST: count 1

For any n-tuple of aggregation keys, each unique combination of values for the keys defines a separate aggregation instance, which WAF counts and rate-limits individually.

You can optionally nest another statement inside the rate-based statement, to narrow the scope of the rule so that it only counts and rate limits requests that match the nested statement. You can use this nested scope-down statement in conjunction with your aggregation key specifications or you can just count and rate limit all requests that match the scope-down statement, without additional aggregation. When you choose to just manage all requests that match a scope-down statement, the aggregation instance is singular for the rule.

You cannot nest a RateBasedStatement inside another statement, for example inside a NotStatement or OrStatement . You can define a RateBasedStatement inside a web ACL and inside a rule group.

For additional information about the options, see Rate limiting web requests using rate-based rules in the WAF Developer Guide .

If you only aggregate on the individual IP address or forwarded IP address, you can retrieve the list of IP addresses that WAF is currently rate limiting for a rule through the API call GetRateBasedStatementManagedKeys . This option is not available for other aggregation configurations.

WAF tracks and manages web requests separately for each instance of a rate-based rule that you use. For example, if you provide the same rate-based rule settings in two web ACLs, each of the two rule statements represents a separate instance of the rate-based rule and gets its own tracking and management by WAF. If you define a rate-based rule inside a rule group, and then use that rule group in multiple places, each use creates a separate instance of the rate-based rule that gets its own tracking and management by WAF.

Limit -> (long)

The limit on requests per 5-minute period for a single aggregation instance for the rate-based rule. If the rate-based statement includes a ScopeDownStatement , this limit is applied only to the requests that match the statement.

Examples:

  • If you aggregate on just the IP address, this is the limit on requests from any single IP address.
  • If you aggregate on the HTTP method and the query argument name “city”, then this is the limit on requests for any single method, city pair.

AggregateKeyType -> (string)

Setting that indicates how to aggregate the request counts.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.
  • CONSTANT - Count and limit the requests that match the rate-based rule’s scope-down statement. With this option, the counted requests aren’t further aggregated. The scope-down statement is the only specification used. When the count of all requests that satisfy the scope-down statement goes over the limit, WAF applies the rule action to all requests that satisfy the scope-down statement. With this option, you must configure the ScopeDownStatement property.
  • CUSTOM_KEYS - Aggregate the request counts using one or more web request components as the aggregate keys. With this option, you must specify the aggregate keys in the CustomKeys property. To aggregate on only the IP address or only the forwarded IP address, don’t use custom keys. Instead, set the aggregate key type to IP or FORWARDED_IP .
  • FORWARDED_IP - Aggregate the request counts on the first IP address in an HTTP header. With this option, you must specify the header to use in the ForwardedIPConfig property. To aggregate on a combination of the forwarded IP address with other aggregate keys, use CUSTOM_KEYS .
  • IP - Aggregate the request counts on the IP address from the web request origin. To aggregate on a combination of the IP address with other aggregate keys, use CUSTOM_KEYS .

( … recursive … )ForwardedIPConfig -> (structure)

The configuration for inspecting IP addresses in an HTTP header that you specify, instead of using the IP address that’s reported by the web request origin. Commonly, this is the X-Forwarded-For (XFF) header, but you can specify any header name.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

This is required if you specify a forwarded IP in the rule’s aggregate key settings.

HeaderName -> (string)

The name of the HTTP header to use for the IP address. For example, to use the X-Forwarded-For (XFF) header, set this to X-Forwarded-For .

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

FallbackBehavior -> (string)

The match status to assign to the web request if the request doesn’t have a valid IP address in the specified position.

Note

If the specified header isn’t present in the request, WAF doesn’t apply the rule to the web request at all.

You can specify the following fallback behaviors:

  • MATCH - Treat the web request as matching the rule statement. WAF applies the rule action to the request.
  • NO_MATCH - Treat the web request as not matching the rule statement.

CustomKeys -> (list)

Specifies the aggregate keys to use in a rate-base rule.

(structure)

Specifies a single custom aggregate key for a rate-base rule.

Note

Web requests that are missing any of the components specified in the aggregation keys are omitted from the rate-based rule evaluation and handling.

Header -> (structure)

Use the value of a header in the request as an aggregate key. Each distinct value in the header contributes to the aggregation instance. If you use a single header as your custom key, then each value fully defines an aggregation instance.

Name -> (string)

The name of the header to use.

TextTransformations -> (list)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection. Text transformations are used in rule match statements, to transform the FieldToMatch request component before inspecting it, and they’re used in rate-based rule statements, to transform request components before using them as custom aggregation keys. If you specify one or more transformations to apply, WAF performs all transformations on the specified content, starting from the lowest priority setting, and then uses the component contents.

(structure)

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

Priority -> (integer)

Sets the relative processing order for multiple transformations. WAF processes all transformations, from lowest priority to highest, before inspecting the transformed content. The priorities don’t need to be consecutive, but they must all be different.

Type -> (string)

You can specify the following transformation types:

BASE64_DECODE - Decode a Base64 -encoded string.

BASE64_DECODE_EXT - Decode a Base64 -encoded string, but use a forgiving implementation that ignores characters that aren’t valid.

CMD_LINE - Command-line transformations. These are helpful in reducing effectiveness of attackers who inject an operating system command-line command and use unusual formatting to disguise some or all of the command.

  • Delete the following characters: \ " ' ^
  • Delete spaces before the following characters: