rules:
- id: missing-csrf-protection
  patterns:
  - pattern: |
      class $CONTROLLER < ActionController::Base
        ...
      end
  - pattern-not: |
      class $CONTROLLER < ActionController::Base
        ...
        protect_from_forgery :with => :exception
      end
  - pattern-not: |
      class $CONTROLLER < ActionController::Base
        ...
        protect_from_forgery prepend: true, with: :exception
      end
  message: >-
    Detected controller which does not enable cross-site request forgery
    protections using 'protect_from_forgery'. Add
    'protect_from_forgery :with => :exception' to your controller class.
  severity: ERROR
  metadata:
    cwe: 'CWE-352: Cross-Site Request Forgery (CSRF)'
    owasp: 'A6: Security Misconfiguration'
    source-rule-url: https://github.com/presidentbeef/brakeman/blob/main/docs/warning_types/cross-site_request_forgery/index.markdown
    category: security
    technology:
    - ruby
  languages:
  - ruby