wafv2 CfHighlander component

Build status

Parameters

Name	Use	Default	Global	Type	Allowed Values
EnvironmentName	Tagging	dev	true	string
EnvironmentType	Tagging	development	true	string	development / production
Scope	Sets the AWS scope of the WebACL	REGIONAL	false	string	REGIONAL / CLOUDFRONT

Outputs/Exports

Name	Value	Exported
RestApiId	RestApiId	true
RestApiStage	RestApiStage	true

Included Components

Example Configuration

Highlander

    Component name: 'wafv2', template: 'wafv2' do
      parameter name: 'Scope', value: 'CLOUDFRONT'
    end

API Gateway (Rest) Configuration

rules:
  AWSManagedRulesAmazonIpReputationList:
    enabled: true
  AWSManagedRulesKnownBadInputsRuleSet:
    enabled: true
  AWSManagedRulesSQLiRuleSet:
    enabled: true
  IPBlacklistRule:
    enabled: true
    priority: 10
    action:
      Block: {}
    statement:
      IPSetReferenceStatement:
        Arn:
          Fn::GetAtt: ['Blacklist', 'Arn']
ipsets:
  Blacklist:
    desc: No more Google DNS
    addresses:
    - 8.8.8.8/32

Configuration

Managed Rules

These are rules that are defined in the wafv2.config.yaml file.

To enable or modify the rules use the following syntax

rules:
  # specify the matching rule name as the key
  AWSManagedRulesCommonRuleSet:
    # when enabled is true the rule is added to the WAF
    enabled: true
    # conditional adds the rule to the WAF if the cloudformation parameter to enable the rule is set to 'true' at runtime
    conditional: false
    # alter the default priority
    priority: 30

Rule	Default Priority	Enabled By Default	AWS Managed
IPSetWhitelist	10	false	false
IPSetBlacklist	20	false	false
AWSManagedRulesCommonRuleSet	30	true	true
AWSManagedRulesAdminProtectionRuleSet	40	false	true
AWSManagedRulesKnownBadInputsRuleSet	50	false	true
AWSManagedRulesSQLiRuleSet	60	false	true
AWSManagedRulesLinuxRuleSet	70	false	true
AWSManagedRulesUnixRuleSet	80	false	true
AWSManagedRulesWindowsRuleSet	90	false	true
AWSManagedRulesPHPRuleSet	100	false	true
AWSManagedRulesWordPressRuleSet	110	false	true
AWSManagedRulesAmazonIpReputationList	120	false	true
AWSManagedRulesAnonymousIpList	130	false	true

Visit the following AWS docs to get the details of the AWS managed rules https://docs.aws.amazon.com/waf/latest/developerguide/aws-managed-rule-groups-list.html

Custom Rules

custom rules can be added using the following syntax

rules:
  MyRule:
    # set the rule priority
    priority: 25
    # specify the action, default action is to block
    action:
      Block: {}
    # set the rule statement using the cloudformation waf rules syntax
    # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-wafv2-webacl-statementone.html
    statement:
      StatementOne: {}

for example creating a IP block on a rate based limit rule. this rule will temporarily block an IP if it reaches 1000 requests within a 5 minute time frame.

rules:
  IPRatelimitBlock:
    priority: 25
    action:
      Block: {}
    statement:
      RateBasedStatement:
        AggregateKeyType: IP
        Limit: 1000

IP Sets

to create static ip white and black lists use the following config:

create the IPSet with an optional description.

ipsets:
  Whitelist:
    # optional
    desc: ips to whitelist for my waf
    addresses:
    - 127.0.0.1/32

the default ip version is IPv4 but can be overridden to IPv6 by setting the version: IPv6.

create a rule using the IPSet

rules:
  IPWhitelistRule:
    priority: 10
    action:
      Allow: {}
    statement: 
      OrStatement:
        Statements:
        - IPSetReferenceStatement:
            Arn: 
              # reference the ipset name in your config
              Fn::GetAtt: ['Whitelist', 'Arn']

Regex Pattern Sets

create the RegexPatternSet with an optional description specifying a list of regexes

pattern_sets:
  MyPattern:
    desc: test pattern
    regexes:
    - '^[\w\-]+$'

create a rule using the RegexPatternSet

rules:
  Regex:
    priority: 10
    action:
      Allow: {}
    statement: 
      RegexPatternSetReferenceStatement:
        Arn:
          # reference the pattern set name in your config
          Fn::GetAtt: ['MyPattern', 'Arn']
        # set the field amd transform properities acording to 
        # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-wafv2-webacl-fieldtomatch.html
        FieldToMatch:
          AllQueryArguments: {}
        TextTransformations:
          - Priority: 1
            Type: NONE

Cfhighlander Setup

install cfhighlander gem

gem install cfhighlander

or via docker

docker pull theonestack/cfhighlander

Testing Components

Running the tests

cfhighlander cftest wafv2