AWS::WAFv2::WebACL
Note
This is the latest version of AWS WAF , named AWS WAFV2, released in November, 2019. For information, including how to migrate your AWS WAF resources from the prior release, see the AWS WAF developer guide.
Use an AWS::WAFv2::WebACL to define a collection of rules to use to inspect and control web requests. Each rule in a web ACL has a statement that defines what to look for in web requests and an action that AWS WAF applies to requests that match the statement. In the web ACL, you assign a default action to take (allow, block) for any request that doesn't match any of the rules.
The rules in a web ACL can be a combination of explicitly defined rules and rule groups that you reference from the web ACL. The rule groups can be rule groups that you manage or rule groups that are managed by others.
You can associate a web ACL with one or more AWS resources to protect. The resources can be an Amazon CloudFront distribution, an Amazon API Gateway REST API, an Application Load Balancer, an AWS AppSync GraphQL API , an Amazon Cognito user pool, an AWS App Runner service, or an AWS Verified Access instance.
For more information, see Web access control lists (web ACLs) in the AWS WAF developer guide.
Web ACLs used in AWS Shield Advanced automatic application layer DDoS mitigation
If you use Shield Advanced automatic application layer DDoS mitigation, the web ACLs that you use
with automatic mitigation have a rule group rule whose name starts with ShieldMitigationRuleGroup
. This rule is
used for automatic mitigations and it's managed for you in the web ACL by Shield Advanced and AWS WAF.
You'll see the rule listed among the web ACL rules when you view the web ACL through the AWS WAF interfaces.
When you manage the web ACL through AWS CloudFormation interfaces, you won't see the Shield Advanced rule. AWS CloudFormation doesn't include this type of rule in the stack drift status between the actual configuration of the web ACL and your web ACL template.
Don't add the Shield Advanced rule group rule to your web ACL template. The rule shouldn't be in your template. When you update the web ACL template in a stack, the Shield Advanced rule is maintained for you by AWS WAF in the resulting web ACL.
For more information, see Shield Advanced automatic application layer DDoS mitigation in the AWS Shield Advanced developer guide.
Syntax
To declare this entity in your AWS CloudFormation template, use the following syntax:
JSON
{ "Type" : "AWS::WAFv2::WebACL", "Properties" : { "AssociationConfig" :
AssociationConfig
, "CaptchaConfig" :CaptchaConfig
, "ChallengeConfig" :ChallengeConfig
, "CustomResponseBodies" :{
, "DefaultAction" :Key
:Value
, ...}DefaultAction
, "Description" :String
, "Name" :String
, "Rules" :[ Rule, ... ]
, "Scope" :String
, "Tags" :[ Tag, ... ]
, "TokenDomains" :[ String, ... ]
, "VisibilityConfig" :VisibilityConfig
} }
YAML
Type: AWS::WAFv2::WebACL Properties: AssociationConfig:
AssociationConfig
CaptchaConfig:CaptchaConfig
ChallengeConfig:ChallengeConfig
CustomResponseBodies:DefaultAction:
Key
:Value
DefaultAction
Description:String
Name:String
Rules:- Rule
Scope:String
Tags:- Tag
TokenDomains:- String
VisibilityConfig:VisibilityConfig
Properties
AssociationConfig
-
Specifies custom configurations for the associations between the web ACL and protected resources.
Use this to customize the maximum size of the request body that your protected resources forward to AWS WAF for inspection. You can customize this setting for CloudFront, API Gateway, Amazon Cognito, App Runner, or Verified Access resources. The default setting is 16 KB (16,384 bytes).
Note
You are charged additional fees when your protected resources forward body sizes that are larger than the default. For more information, see AWS WAF Pricing
. For Application Load Balancer and AWS AppSync, the limit is fixed at 8 KB (8,192 bytes).
Required: No
Type: AssociationConfig
Update requires: No interruption
CaptchaConfig
-
Specifies how AWS WAF should handle
CAPTCHA
evaluations for rules that don't have their ownCaptchaConfig
settings. If you don't specify this, AWS WAF uses its default settings forCaptchaConfig
.Required: No
Type: CaptchaConfig
Update requires: No interruption
ChallengeConfig
-
Specifies how AWS WAF should handle challenge evaluations for rules that don't have their own
ChallengeConfig
settings. If you don't specify this, AWS WAF uses its default settings forChallengeConfig
.Required: No
Type: ChallengeConfig
Update requires: No interruption
CustomResponseBodies
-
A map of custom response keys and content bodies. When you create a rule with a block action, you can send a custom response to the web request. You define these for the web ACL, and then use them in the rules and default actions that you define in the web ACL.
For information about customizing web requests and responses, see Customizing web requests and responses in AWS WAF in the AWS WAF Developer Guide.
For information about the limits on count and size for custom request and response settings, see AWS WAF quotas in the AWS WAF Developer Guide.
Required: No
Type: Object of CustomResponseBody
Update requires: No interruption
DefaultAction
-
The action to perform if none of the
Rules
contained in theWebACL
match.Required: Yes
Type: DefaultAction
Update requires: No interruption
Description
-
A description of the web ACL that helps with identification.
Required: No
Type: String
Pattern:
^[a-zA-Z0-9=:#@/\-,.][a-zA-Z0-9+=:#@/\-,.\s]+[a-zA-Z0-9+=:#@/\-,.]{1,256}$
Update requires: No interruption
Name
-
The name of the web ACL. You cannot change the name of a web ACL after you create it.
Required: No
Type: String
Pattern:
^[0-9A-Za-z_-]{1,128}$
Update requires: Replacement
Rules
-
The rule statements used to identify the web requests that you want to manage. Each rule includes one top-level statement that AWS WAF uses to identify matching web requests, and parameters that govern how AWS WAF handles them.
Required: No
Type: Array of Rule
Update requires: No interruption
Scope
-
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 AWS AppSync GraphQL API, an Amazon Cognito user pool, an AWS App Runner service, or an AWS Verified Access instance. Valid Values are
CLOUDFRONT
andREGIONAL
.Note
For
CLOUDFRONT
, you must create your WAFv2 resources in the US East (N. Virginia) Region,us-east-1
.For information about how to define the association of the web ACL with your resource, see AWS::WAFv2::WebACLAssociation.
Required: Yes
Type: String
Allowed values:
CLOUDFRONT | REGIONAL
Update requires: Replacement
-
Key:value pairs associated with an AWS resource. The key:value pair can be anything you define. Typically, the tag key represents a category (such as "environment") and the tag value represents a specific value within that category (such as "test," "development," or "production"). You can add up to 50 tags to each AWS resource.
Note
To modify tags on existing resources, use the AWS WAF APIs or command line interface. With AWS CloudFormation, you can only add tags to AWS WAF resources during resource creation.
Required: No
Type: Array of Tag
Minimum:
1
Update requires: No interruption
TokenDomains
-
Specifies the domains that AWS WAF should accept in a web request token. This enables the use of tokens across multiple protected websites. When AWS WAF provides a token, it uses the domain of the AWS resource that the web ACL is protecting. If you don't specify a list of token domains, AWS WAF accepts tokens only for the domain of the protected resource. With a token domain list, AWS WAF accepts the resource's host domain plus all domains in the token domain list, including their prefixed subdomains.
Required: No
Type: Array of String
Minimum:
1
Maximum:
253
Update requires: No interruption
VisibilityConfig
-
Defines and enables Amazon CloudWatch metrics and web request sample collection.
Required: Yes
Type: VisibilityConfig
Update requires: No interruption
Return values
Ref
The Ref
for the resource, containing the resource name, physical ID, and scope, formatted as follows: name|id|scope
.
For example: my-webacl-name|1234a1a-a1b1-12a1-abcd-a123b123456|REGIONAL
.
Fn::GetAtt
The Fn::GetAtt
intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.
For more information about using the Fn::GetAtt
intrinsic function, see Fn::GetAtt
.
Arn
-
The Amazon Resource Name (ARN) of the web ACL.
Capacity
-
The web ACL capacity units (WCUs) currently being used by this web ACL.
AWS WAF uses WCUs to calculate and control the operating resources that are used to run your rules, rule groups, and web ACLs. AWS WAF calculates capacity differently for each rule type, to reflect the relative cost of each rule. Simple rules that cost little to run use fewer WCUs than more complex rules that use more processing power. Rule group capacity is fixed at creation, which helps users plan their web ACL WCU usage when they use a rule group. The WCU limit for web ACLs is 1,500.
Id
-
The ID of the web ACL.
LabelNamespace
-
The label namespace prefix for this web ACL. All labels added by rules in this web ACL have this prefix.
The syntax for the label namespace prefix for a web ACL is the following:
awswaf:<account ID>:webacl:<web ACL name>:
When a rule with a label matches a web request, AWS WAF adds the fully qualified label to the request. A fully qualified label is made up of the label namespace from the rule group or web ACL where the rule is defined and the label from the rule, separated by a colon.
Examples
Create a web ACL with a variety of rate-based rules
The following example web ACL specification shows a number of rate-based rules. For information about each rule, see the
examples under AWS::WAFv2::WebACL RateBasedStatement
.
YAML
Name: exampleWebACL Id: exampleWebACLExampleID ARN: arn:aws:wafv2:us-east-1:ExampleAccountNumber:regional/webacl/exampleWebACL/exampleWebACLExampleID DefaultAction: Allow: {} Description: '' Rules: - Name: rbrCountAll Priority: 0 Statement: RateBasedStatement: Limit: 100000 AggregateKeyType: CONSTANT ScopeDownStatement: GeoMatchStatement: CountryCodes: - GB ForwardedIPConfig: HeaderName: X-Forwarded-For FallbackBehavior: MATCH Action: Block: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: rbrCountAll - Name: rbrNoCustomKeys Priority: 1 Statement: RateBasedStatement: Limit: 1000 AggregateKeyType: FORWARDED_IP ForwardedIPConfig: HeaderName: X-Forwarded-For FallbackBehavior: MATCH Action: Block: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: rbrNoCustomKeys - Name: rbrCustomKeysA Priority: 2 Statement: RateBasedStatement: Limit: 2000 AggregateKeyType: CUSTOM_KEYS ForwardedIPConfig: HeaderName: X-Forwarded-For FallbackBehavior: MATCH CustomKeys: - Header: Name: Content-Type TextTransformations: - Priority: 0 Type: NONE - ForwardedIP: {} Action: Block: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: rbrCustomKeysA - Name: rbrCustomKeysB Priority: 3 Statement: RateBasedStatement: Limit: 3000 AggregateKeyType: CUSTOM_KEYS CustomKeys: - QueryString: TextTransformations: - Priority: 0 Type: NONE - HTTPMethod: {} - UriPath: TextTransformations: - Priority: 0 Type: NONE Action: Block: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: rbrCustomKeysB - Name: labelUSStates Priority: 4 Statement: GeoMatchStatement: CountryCodes: - US Action: Count: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: labelUSStates - Name: rbrRequestsFromUSStates Priority: 5 Statement: RateBasedStatement: Limit: 500 AggregateKeyType: CUSTOM_KEYS ScopeDownStatement: GeoMatchStatement: CountryCodes: - US CustomKeys: - LabelNamespace: Namespace: 'awswaf:clientip:geo:region:' Action: Block: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: rbrRequestsFromUSStates VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: exampleWebACL Capacity: 193 ManagedByFirewallManager: false LabelNamespace: 'awswaf:ExampleAccountNumber:webacl:exampleWebACL:'
JSON
{ "Name": "exampleWebACL", "Id": "exampleWebACLExampleID", "ARN": "arn:aws:wafv2:us-east-1:ExampleAccountNumber:regional/webacl/exampleWebACL/exampleWebACLExampleID", "DefaultAction": { "Allow": {} }, "Description": "", "Rules": [ { "Name": "rbrCountAll", "Priority": 0, "Statement": { "RateBasedStatement": { "Limit": 100000, "AggregateKeyType": "CONSTANT", "ScopeDownStatement": { "GeoMatchStatement": { "CountryCodes": [ "GB" ], "ForwardedIPConfig": { "HeaderName": "X-Forwarded-For", "FallbackBehavior": "MATCH" } } } } }, "Action": { "Block": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "rbrCountAll" } }, { "Name": "rbrNoCustomKeys", "Priority": 1, "Statement": { "RateBasedStatement": { "Limit": 1000, "AggregateKeyType": "FORWARDED_IP", "ForwardedIPConfig": { "HeaderName": "X-Forwarded-For", "FallbackBehavior": "MATCH" } } }, "Action": { "Block": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "rbrNoCustomKeys" } }, { "Name": "rbrCustomKeysA", "Priority": 2, "Statement": { "RateBasedStatement": { "Limit": 2000, "AggregateKeyType": "CUSTOM_KEYS", "ForwardedIPConfig": { "HeaderName": "X-Forwarded-For", "FallbackBehavior": "MATCH" }, "CustomKeys": [ { "Header": { "Name": "Content-Type", "TextTransformations": [ { "Priority": 0, "Type": "NONE" } ] } }, { "ForwardedIP": {} } ] } }, "Action": { "Block": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "rbrCustomKeysA" } }, { "Name": "rbrCustomKeysB", "Priority": 3, "Statement": { "RateBasedStatement": { "Limit": 3000, "AggregateKeyType": "CUSTOM_KEYS", "CustomKeys": [ { "QueryString": { "TextTransformations": [ { "Priority": 0, "Type": "NONE" } ] } }, { "HTTPMethod": {} }, { "UriPath": { "TextTransformations": [ { "Priority": 0, "Type": "NONE" } ] } } ] } }, "Action": { "Block": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "rbrCustomKeysB" } }, { "Name": "labelUSStates", "Priority": 4, "Statement": { "GeoMatchStatement": { "CountryCodes": [ "US" ] } }, "Action": { "Count": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "labelUSStates" } }, { "Name": "rbrRequestsFromUSStates", "Priority": 5, "Statement": { "RateBasedStatement": { "Limit": 500, "AggregateKeyType": "CUSTOM_KEYS", "ScopeDownStatement": { "GeoMatchStatement": { "CountryCodes": [ "US" ] } }, "CustomKeys": [ { "LabelNamespace": { "Namespace": "awswaf:clientip:geo:region:" } } ] } }, "Action": { "Block": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "rbrRequestsFromUSStates" } } ], "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "exampleWebACL" }, "Capacity": 193, "ManagedByFirewallManager": false, "LabelNamespace": "awswaf:ExampleAccountNumber:webacl:exampleWebACL:" }
Create a web ACL with custom request and response handling
The following shows an example web ACL specification. This example includes custom request and response configurations.
YAML
ExampleWebACL: Type: 'AWS::WAFv2::WebACL' Properties: Name: ExampleWebACL1 Scope: REGIONAL Description: This is an example WebACL DefaultAction: Allow: CustomRequestHandling: InsertHeaders: - Name: AllowActionHeader1Name Value: AllowActionHeader1Value - Name: AllowActionHeader2Name Value: AllowActionHeader2Value VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: ExampleWebACLMetric CustomResponseBodies: CustomResponseBodyKey1: ContentType: TEXT_PLAIN Content: this is a plain text CustomResponseBodyKey2: ContentType: APPLICATION_JSON Content: '{"jsonfieldname": "jsonfieldvalue"}' CustomResponseBodyKey3: ContentType: TEXT_HTML Content: <html>HTML text content</html> Rules: - Name: RuleWithAWSManagedRules Priority: 0 OverrideAction: Count: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: RuleWithAWSManagedRulesMetric Statement: ManagedRuleGroupStatement: VendorName: AWS Name: AWSManagedRulesCommonRuleSet ExcludedRules: [] - Name: BlockXssAttack Priority: 1 Action: Block: CustomResponse: ResponseCode: 503 CustomResponseBodyKey: CustomResponseBodyKey1 ResponseHeaders: - Name: BlockActionHeader1Name Value: BlockActionHeader1Value - Name: BlockActionHeader2Name Value: BlockActionHeader2Value VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: BlockXssAttackMetric Statement: XssMatchStatement: FieldToMatch: AllQueryArguments: {} TextTransformations: - Priority: 1 Type: NONE
JSON
"ExampleWebACL": { "Type": "AWS::WAFv2::WebACL", "Properties": { "Name": "ExampleWebACL1", "Scope": "REGIONAL", "Description": "This is an example WebACL", "DefaultAction": { "Allow": { "CustomRequestHandling": { "InsertHeaders": [ { "Name": "AllowActionHeader1Name", "Value": "AllowActionHeader1Value" }, { "Name": "AllowActionHeader2Name", "Value": "AllowActionHeader2Value" } ] } } }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "ExampleWebACLMetric" }, "CustomResponseBodies": { "CustomResponseBodyKey1": { "ContentType": "TEXT_PLAIN", "Content": "this is a plain text" }, "CustomResponseBodyKey2": { "ContentType": "APPLICATION_JSON", "Content": "{\"jsonfieldname\": \"jsonfieldvalue\"}" }, "CustomResponseBodyKey3": { "ContentType": "TEXT_HTML", "Content": "<html>HTML text content</html>" } }, "Rules": [ { "Name": "RuleWithAWSManagedRules", "Priority": 0, "OverrideAction": { "Count": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "RuleWithAWSManagedRulesMetric" }, "Statement": { "ManagedRuleGroupStatement": { "VendorName": "AWS", "Name": "AWSManagedRulesCommonRuleSet", "ExcludedRules": [] } } }, { "Name": "BlockXssAttack", "Priority": 1, "Action": { "Block": { "CustomResponse": { "ResponseCode": 503, "CustomResponseBodyKey": "CustomResponseBodyKey1", "ResponseHeaders": [ { "Name": "BlockActionHeader1Name", "Value": "BlockActionHeader1Value" }, { "Name": "BlockActionHeader2Name", "Value": "BlockActionHeader2Value" } ] } } }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "BlockXssAttackMetric" }, "Statement": { "XssMatchStatement": { "FieldToMatch": { "AllQueryArguments": {} }, "TextTransformations": [ { "Priority": 1, "Type": "NONE" } ] } } } ] } }
Create a web ACL with JSON body parsing
The following shows an example web ACL specification. This example includes inspection of the web request body as JSON.
YAML
ExampleWebACL: Type: 'AWS::WAFv2::WebACL' Properties: Name: TestingJsonBody Scope: REGIONAL Description: WebACL for JsonBody Testing DefaultAction: Allow: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: ExampleWebACLMetric Rules: - Name: TestJsonBodyRule Priority: 0 Action: Block: {} VisibilityConfig: SampledRequestsEnabled: true CloudWatchMetricsEnabled: true MetricName: JsonBodyMatchMetric Statement: ByteMatchStatement: FieldToMatch: JsonBody: MatchPattern: IncludedPaths: - /foo - /bar MatchScope: VALUE InvalidFallbackBehavior: MATCH PositionalConstraint: EXACTLY SearchString: BadBot TextTransformations: - Type: NONE Priority: 0
JSON
"ExampleWebACL": { "Type": "AWS::WAFv2::WebACL", "Properties": { "Name": "TestingJsonBody", "Scope": "REGIONAL", "DefaultAction": { "Allow": {} }, "Description": "WebACL for JsonBody Testing", "Rules": [ { "Name": "TestJsonBodyRule", "Priority": 1, "Statement": { "ByteMatchStatement": { "SearchString": "BadBot", "FieldToMatch": { "JsonBody": { "MatchPattern": { "IncludedPaths": [ "/foo", "/bar" ] }, "MatchScope": "VALUE", "InvalidFallbackBehavior": "MATCH" } }, "TextTransformations": [ { "Priority": 1, "Type": "NONE" } ], "PositionalConstraint": "EXACTLY" } }, "Action": { "Block": {} }, "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "JsonBodyMatchMetric" } } ], "VisibilityConfig": { "SampledRequestsEnabled": true, "CloudWatchMetricsEnabled": true, "MetricName": "TestingJsonBodyMetric" } } }