mcp-server-semgrep/semgrep-rules/python/django/security/injection/path-traversal/path-traversal-file-name.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: path-traversal-file-name
  message: >-
    Data from request is passed to a file name `$FILE`. This is a path traversal vulnerability, which
    can lead to sensitive data being leaked. To mitigate, consider using os.path.abspath or os.path.realpath
    or the pathlib library.
  metadata:
    cwe:
    - "CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')"
    owasp:
    - A05:2017 - Broken Access Control
    - A01:2021 - Broken Access Control
    references:
    - https://owasp.org/www-community/attacks/Path_Traversal
    category: security
    technology:
    - django
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - vuln
    likelihood: LOW
    impact: MEDIUM
    confidence: LOW
  patterns:
  - pattern-inside: |
      def $F(...):
        ...
  - pattern-not-inside: |
      def $F(...):
        ...
        os.path.realpath(...)
        ...
  - pattern-not-inside: |
      def $F(...):
        ...
        os.path.abspath(...)
        ...
  - pattern-either:
          # match % use cases
    - pattern: |
        $V = request.$W.get($X)
        ...
        $FILE % ($V)
    - pattern: |
        $V = request.$W[$X]
        ...
        $FILE % ($V)
    - pattern: |
        $V = request.$W($X)
        ...
        $FILE % ($V)
    - pattern: |
        $V = request.$W
        ...
        $FILE % ($V)
        # match format use cases
    - pattern: |
        $V = request.$W.get($X)
        ...
        $FILE.format(..., $V, ...)
    - pattern: |
        $V = request.$W[$X]
        ...
        $FILE.format(..., $V, ...)
    - pattern: |
        $V = request.$W($X)
        ...
        $FILE.format(..., $V, ...)
    - pattern: |
        $V = request.$W
        ...
        $FILE.format(..., $V, ...)
  - metavariable-regex:
      metavariable: $FILE
      regex: .*\.(log|zip|txt|csv|xml|html).*
  languages: [python]
  severity: WARNING