mcp-server-semgrep/semgrep-rules/ruby/rails/security/brakeman/check-unsafe-reflection-methods.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: check-unsafe-reflection-methods
  mode: taint
  pattern-sources:
  - pattern-either:
    - pattern: |
        cookies[...]
    - patterns:
      - pattern: |
          cookies. ... .$PROPERTY[...]
      - metavariable-regex:
          metavariable: $PROPERTY
          regex: (?!signed|encrypted)
    - pattern: |
        params[...]
    - pattern: |
        request.env[...]
  pattern-sinks:
  - patterns:
    - pattern: $X
    - pattern-either:
      - pattern-inside: |
          $X. ... .to_proc
      - patterns:
          - pattern-inside: |
              $Y.method($Z)
          - focus-metavariable: $Z
      - patterns:
          - pattern-inside: |
              $Y.tap($Z)
          - focus-metavariable: $Z
      - patterns:
          - pattern-inside: |
              $Y.tap{ |$ANY| $Z }
          - focus-metavariable: $Z
  message: Found user-controllable input to a reflection method. This may allow a user to alter program
    behavior and potentially execute arbitrary instructions in the context of the process. Do not provide
    arbitrary user input to `tap`, `method`, or `to_proc`
  languages:
  - ruby
  severity: ERROR
  metadata:
    source-rule-url: https://github.com/presidentbeef/brakeman/blob/main/lib/brakeman/checks/check_unsafe_reflection_methods.rb
    category: security
    cwe:
    - "CWE-94: Improper Control of Generation of Code ('Code Injection')"
    owasp:
    - A03:2021 - Injection
    technology:
    - ruby
    - rails
    references:
    - https://github.com/presidentbeef/brakeman/blob/main/test/apps/rails6/app/controllers/groups_controller.rb
    cwe2022-top25: true
    subcategory:
    - vuln
    likelihood: MEDIUM
    impact: MEDIUM
    confidence: MEDIUM