mcp-server-semgrep/semgrep-rules/typescript/react/security/react-markdown-insecure-html.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: react-markdown-insecure-html
  message: >-
    Overwriting `transformLinkUri` or `transformImageUri` to something insecure, or turning `allowDangerousHtml`
    on, or turning `escapeHtml` off, will open the code up to XSS vectors.
  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://www.npmjs.com/package/react-markdown#security
    category: security
    technology:
    - react
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - audit
    likelihood: LOW
    impact: LOW
    confidence: LOW
  languages:
  - typescript
  - javascript
  severity: WARNING
  patterns:
  - pattern-either:
    - pattern-inside: |
        $X = require('react-markdown/with-html');
        ...
    - pattern-inside: |
        $X = require('react-markdown');
        ...
    - pattern-inside: |
        import 'react-markdown/with-html';
        ...
    - pattern-inside: |
        import 'react-markdown';
        ...
  - pattern-either:
    - pattern: |
        <$EL allowDangerousHtml />
    - pattern: |
        <$EL escapeHtml={false} />
    - pattern: |
        <$EL transformLinkUri=... />
    - pattern: |
        <$EL transformImageUri=... />