mcp-server-semgrep/semgrep-rules/javascript/lang/security/audit/unknown-value-with-script-tag.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: unknown-value-with-script-tag
  message: >-
    Cannot determine what '$UNK' is and it is used with a '<script>' tag. This
    could be susceptible to cross-site scripting (XSS). Ensure '$UNK' is not
    externally controlled, or sanitize this data.
  metadata:
    owasp:
    - A07:2017 - Cross-Site Scripting (XSS)
    - A03:2021 - Injection
    cwe:
    - "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"
    references:
    - https://www.developsec.com/2017/11/09/xss-in-a-script-tag/
    - https://github.com/juice-shop/juice-shop/blob/1ceb8751e986dacd3214a618c37e7411be6bc11a/routes/videoHandler.ts#L68
    category: security
    technology:
    - javascript
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - audit
    likelihood: LOW
    impact: LOW
    confidence: LOW
  languages:
  - javascript
  - typescript
  severity: WARNING
  patterns:
  - pattern-inside: |
      $UNK = $ANYFUNC(...);
      ...
      $OTHERFUNC(..., <... $UNK ...>, ...);
  - pattern: $OTHERFUNC(..., <... "=~/.*<script.*/" ...>, ...)
  - pattern: $UNK