AWS::WAFv2::WebACL - AWS CloudFormation

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 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 contain rule statements that you define explicitly and rule statements that reference rule groups and managed rule groups. 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, or an AWS AppSync GraphQL API.

Syntax

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

JSON

{ "Type" : "AWS::WAFv2::WebACL", "Properties" : { "CustomResponseBodies" : {Key : Value, ...}, "DefaultAction" : DefaultAction, "Description" : String, "Name" : String, "Rules" : [ Rule, ... ], "Scope" : String, "Tags" : [ Tag, ... ], "VisibilityConfig" : VisibilityConfig } }

YAML

Type: AWS::WAFv2::WebACL Properties: CustomResponseBodies: Key : Value DefaultAction: DefaultAction Description: String Name: String Rules: - Rule Scope: String Tags: - Tag VisibilityConfig: VisibilityConfig

Properties

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: Map of CustomResponseBody

Update requires: No interruption

DefaultAction

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

Required: Yes

Type: DefaultAction

Update requires: No interruption

Description

A description of the web ACL that helps with identification.

Required: No

Type: String

Minimum: 1

Maximum: 256

Pattern: ^[\w+=:#@/\-,\.][\w+=:#@/\-,\.\s]+[\w+=:#@/\-,\.]$

Update requires: No interruption

Name

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

Required: No

Type: String

Minimum: 1

Maximum: 128

Pattern: ^[\w\-]+$

Update requires: Replacement

Rules

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 AWS WAF uses to identify matching web requests, and parameters that govern how AWS WAF handles them.

Required: No

Type: List 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, or an AWS AppSync GraphQL API. Valid Values are CLOUDFRONT and REGIONAL.

Note

For CLOUDFRONT, you must create your WAFv2 resources in the US East (N. Virginia) Region, us-east-1.

Required: Yes

Type: String

Update requires: Replacement

Tags

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: List of Tag

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

Arn

The Amazon Resource Name (ARN) of the web ACL.

Capacity

The current web ACL capacity (WCU) usage by the web ACL.

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 custom request and response handling

The following shows an example web ACL specification. This example includes custom request and response configurations.

YAML

Description: Create WebACL example Resources: 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

"Description": "Create WebACL example", "Resources": { "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

Resources: 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

{ "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"} }