mcp-server-semgrep/semgrep-rules/python/aws-lambda/security/dangerous-subprocess-use.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: dangerous-subprocess-use
  mode: taint
  message: >-
    Detected subprocess function with argument tainted by an `event` object. 
    If this data can be controlled by a malicious actor, it may be an instance of
    command injection. The default option for `shell` is False, and this is secure by default.
    Consider removing the `shell=True` or setting it to False explicitely.
    Using `shell=False` means you have to split the command string into an array of
    strings for the command and its arguments. You may consider using 'shlex.split()' for this purpose.
  metadata:
    owasp:
    - A01:2017 - Injection
    - A03:2021 - Injection
    cwe:
    - "CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')"
    asvs:
      section: 'V5: Validation, Sanitization and Encoding Verification Requirements'
      control_id: 5.3.8 OS Command Injection
      control_url: https://github.com/OWASP/ASVS/blob/master/4.0/en/0x13-V5-Validation-Sanitization-Encoding.md#v53-output-encoding-and-injection-prevention-requirements
      version: '4'
    references:
    - https://docs.python.org/3/library/subprocess.html
    - https://docs.python.org/3/library/shlex.html
    category: security
    technology:
    - python
    - aws-lambda
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - vuln
    likelihood: HIGH
    impact: MEDIUM
    confidence: MEDIUM
  languages:
  - python
  severity: ERROR
  pattern-sources:
  - patterns:
    - pattern: event
    - pattern-inside: |
        def $HANDLER(event, context):
          ...
  pattern-sinks:
  - patterns:
    - pattern: subprocess.$FUNC(..., shell=True, ...)
  pattern-sanitizers:
  - pattern: shlex.split(...)
  - pattern: pipes.quote(...)
  - pattern: shlex.quote(...)