AWS::WAFv2::WebACL Headers

Inspect all headers in the web request. You can specify the parts of the headers to inspect and you can narrow the set of headers to inspect by including or excluding specific keys.

This is used to indicate the web request component to inspect, in the FieldToMatch specification.

If you want to inspect just the value of a single header, use the SingleHeader FieldToMatch setting instead.

Example JSON: "Headers": { "MatchPattern": { "All": {} }, "MatchScope": "KEY", "OversizeHandling": "MATCH" }

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

JSON

{
  "MatchPattern" : HeaderMatchPattern,
  "MatchScope" : String,
  "OversizeHandling" : String
}

YAML

  MatchPattern: 
    HeaderMatchPattern
  MatchScope: String
  OversizeHandling: String

Properties

MatchPattern

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" ] }

Required: Yes

Type: HeaderMatchPattern

Update requires: No interruption

MatchScope

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

All does not require a match to be found in the keys and a match to be found in the values. It requires a match to be found in the keys or the values or both. To require a match in the keys and in the values, use a logical AND statement to combine two match rules, one that inspects the keys and another that inspects the values.

Required: Yes

Type: String

Allowed values: ALL | KEY | VALUE

Update requires: No interruption

OversizeHandling

What AWS WAF should do if the headers of the request are more numerous or larger than AWS WAF can inspect. AWS 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 AWS WAF.

The options for oversize handling are the following:

• CONTINUE - Inspect the available headers normally, according to the rule inspection criteria.

• MATCH - Treat the web request as matching the rule statement. AWS WAF applies the rule action to the request.

• NO_MATCH - Treat the web request as not matching the rule statement.

Required: Yes

Type: String

Allowed values: CONTINUE | MATCH | NO_MATCH

Update requires: No interruption

Examples

Set the Headers specification

The following shows an example Headers field to match specification.

YAML

FieldToMatch:
  Headers:
    MatchPattern:
      IncludedHeaders:
      - "User-Agent"
      - "Referer"
    MatchScope: ALL 
    OversizeHandling: MATCH 

JSON

"FieldToMatch": {
  "Headers": {
    "MatchPattern": {
      "IncludedHeaders": [
        "User-Agent",
        "Referer"
      ]
    },
    "MatchScope": "ALL",
    "OversizeHandling": "MATCH" 
  }
}