mcp-server-semgrep/semgrep-rules/python/lang/security/audit/dangerous-system-call-audit.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: dangerous-system-call-audit
  patterns:
  - pattern-not: os.$W("...", ...)
  - pattern-either:
    - pattern: os.system(...)
    - pattern: getattr(os, "system")(...)
    - pattern: __import__("os").system(...)
    - pattern: getattr(__import__("os"), "system")(...)
    - pattern: |
        $X = __import__("os")
        ...
        $X.system(...)
    - pattern: |
        $X = __import__("os")
        ...
        getattr($X, "system")(...)
    - pattern: |
        $X = getattr(os, "system")
        ...
        $X(...)
    - pattern: |
        $X = __import__("os")
        ...
        $Y = getattr($X, "system")
        ...
        $Y(...)
    - pattern: os.popen(...)
    - pattern: os.popen2(...)
    - pattern: os.popen3(...)
    - pattern: os.popen4(...)
  message: >-
    Found dynamic content used in a system call. This is dangerous if external
    data can reach this function call because it allows a malicious actor to
    execute commands. Use the 'subprocess' module instead, which is easier
    to use without accidentally exposing a command injection vulnerability.
  metadata:
    source-rule-url: https://bandit.readthedocs.io/en/latest/plugins/b605_start_process_with_a_shell.html
    cwe:
    - "CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')"
    owasp:
    - A01:2017 - Injection
    - A03:2021 - Injection
    references:
    - https://semgrep.dev/docs/cheat-sheets/python-command-injection/
    asvs:
      section: 'V5: Validation, Sanitization and Encoding Verification Requirements'
      control_id: 5.2.4 Dyanmic Code Execution Features
      control_url: https://github.com/OWASP/ASVS/blob/master/4.0/en/0x13-V5-Validation-Sanitization-Encoding.md#v52-sanitization-and-sandboxing-requirements
      version: '4'
    category: security
    technology:
    - python
    confidence: LOW
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - audit
    likelihood: LOW
    impact: HIGH
  languages: [python]
  severity: ERROR