mcp-server-semgrep/semgrep-rules/python/flask/security/xss/audit/explicit-unescape-with-markup.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: explicit-unescape-with-markup
  message: >-
    Detected explicitly unescaped content using 'Markup()'. This permits
    the unescaped data to include unescaped HTML which could result in
    cross-site scripting. Ensure this data is not externally controlled,
    or consider rewriting to not use 'Markup()'.
  metadata:
    cwe:
    - "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"
    owasp:
    - A07:2017 - Cross-Site Scripting (XSS)
    - A03:2021 - Injection
    references:
    - https://tedboy.github.io/flask/generated/generated/flask.Markup.html
    category: security
    technology:
    - flask
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - audit
    likelihood: LOW
    impact: MEDIUM
    confidence: LOW
  languages:
  - python
  severity: WARNING
  pattern-either:
  - pattern: flask.Markup.unescape(...)
  - pattern: $MARKUPOBJ.unescape()
  - patterns:
    - pattern-either:
      - pattern: flask.Markup($Q)
      - pattern: markupsafe.Markup($Q)
    - metavariable-pattern:
        metavariable: $Q
        patterns:
        - pattern-not: '"..."'