mcp-server-semgrep/semgrep-rules/python/flask/security/unsanitized-input.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: response-contains-unsanitized-input
  message: >-
    Flask response reflects unsanitized user input. This could lead to a
    cross-site scripting vulnerability (https://owasp.org/www-community/attacks/xss/)
    in which an attacker causes arbitrary code to be executed in the user's browser.
    To prevent, please sanitize the user input, e.g. by rendering the response
    in a Jinja2 template (see considerations in https://flask.palletsprojects.com/en/1.0.x/security/).
  metadata:
    cwe:
    - "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"
    owasp:
    - A07:2017 - Cross-Site Scripting (XSS)
    - A03:2021 - Injection
    references:
    - https://flask.palletsprojects.com/en/1.0.x/security/
    - https://owasp.org/www-community/attacks/xss/
    category: security
    technology:
    - flask
    cwe2022-top25: true
    cwe2021-top25: true
    subcategory:
    - audit
    likelihood: LOW
    impact: MEDIUM
    confidence: LOW
  languages: [python]
  severity: WARNING
  pattern-either:
  - pattern: |
      $X = flask.request.args.get(...)
      ...
      flask.make_response("...".format($X))
  - pattern: |
      $X = flask.request.args.get(...)
      ...
      flask.make_response(f"...{$X}...")
  - pattern: |
      $X = flask.request.args.get(...)
      ...
      flask.make_response(f"...{$X}")
  - pattern: |
      $X = flask.request.args.get(...)
      ...
      flask.make_response(f"{$X}...")