mcp-server-semgrep/semgrep-rules/javascript/lang/security/audit/path-traversal/path-join-resolve-traversal.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: path-join-resolve-traversal
  message: >-
    Detected possible user input going into a `path.join` or `path.resolve`
    function. This could possibly lead to a path traversal vulnerability, 
    where the attacker can access arbitrary files stored in the file system.
    Instead, be sure to sanitize or validate user input first.
  metadata:
    owasp:
    - A05:2017 - Broken Access Control
    - A01:2021 - Broken Access Control
    cwe:
    - "CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')"
    category: security
    references:
    - https://owasp.org/www-community/attacks/Path_Traversal
    technology:
    - javascript
    - node.js
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - vuln
    likelihood: HIGH
    impact: MEDIUM
    confidence: LOW
  languages:
  - javascript
  - typescript
  severity: WARNING
  mode: taint
  pattern-sources:
  - patterns:
    - focus-metavariable: $X
    - pattern-either:
      - pattern-inside: |
          function ... (...,$X,...) {...}
      - pattern-inside: |
          function ... (...,{...,$X,...},...) {...}
  pattern-sinks:
  - patterns:
    - focus-metavariable: $SINK
    - pattern-either:
      - pattern-inside: |
          $PATH = require('path');
          ...
      - pattern-inside: |
          import $PATH from 'path';
          ...
    - pattern-either:
      - pattern: $PATH.join(...,$SINK,...)
      - pattern: $PATH.resolve(...,$SINK,...)
  - patterns:
    - focus-metavariable: $SINK
    - pattern-inside: |
        import 'path';
        ...
    - pattern-either:
      - pattern-inside: path.join(...,$SINK,...)
      - pattern-inside: path.resolve(...,$SINK,...)
  pattern-sanitizers:
  - pattern: $Y.replace(...)
  - pattern: $Y.indexOf(...)
  - pattern: |
      function ... (...) {
          ...
          <... $Y.indexOf(...) ...>
          ...
      }
  - patterns:
    - pattern: $FUNC(...)
    - metavariable-regex:
        metavariable: $FUNC
        regex: sanitize