Resolve vulnerability: Active debug code

Alexander Dessrequested to merge
remediate/active-debug-code-D20251105T134857 into main

MR created from vulnerability: Active debug code

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Description:

The Flask application is running with debug=True configured. By enabling this option, certain exceptions or errors could cause sensitive information to be leaked in HTTP responses.

Additionally, it is not recommended to run a Flask application using Flask.run(...) in production. Instead, a WSGI server such as gunicorn or waitress be used instead.

For more information on deployment options for Flask applications see:

Summary:

Vulnerability Analysis and Fix

Reported Vulnerability

The vulnerability report identified that the Flask application is running with debug=True configured, which can lead to sensitive information being leaked in HTTP responses when exceptions or errors occur. Additionally, the report notes that using Flask.run() is not recommended for production environments.

Security Implications

  1. Debug Mode Enabled: When Flask runs in debug mode, it provides detailed error pages that expose:

    • Stack traces
    • Local variables
    • Application code
    • Environment information

    This information could help attackers understand the application structure and potentially find other vulnerabilities.

  2. Development Server in Production: Flask's built-in server (invoked via app.run()) is not designed for production use as it:

    • Doesn't handle high loads efficiently
    • Lacks security hardening
    • Doesn't provide features like worker management that production WSGI servers offer

Fix Implementation

The fix addresses the immediate security concern by:

  1. Disabling debug mode by changing app.run(debug=True) to app.run(debug=False, host='127.0.0.1')
  2. Restricting the server to only listen on localhost for added security

Additional Recommendations

For a complete solution in a production environment:

  1. Use a production-grade WSGI server like Gunicorn or Waitress:

    # Example with Waitress
from waitress import serve
serve(app, host='0.0.0.0', port=8080)

  2. Consider using environment variables to control configuration:

    import os
debug_mode = os.environ.get('FLASK_DEBUG', 'False').lower() == 'true'
app.run(debug=debug_mode)

  3. Implement proper error handling to avoid exposing sensitive information even when exceptions occur.

This fix addresses the CWE-489 (Active Debug Code) vulnerability by ensuring that debug features are disabled in environments where they could pose a security risk.

Identifiers:

  • A6:2017 - Security Misconfiguration
  • A05:2021 - Security Misconfiguration
  • bandit.B201
  • CWE-489
  • Bandit Test ID B201

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