Python web framework security comparison¶

1. Django

Security strengths:

• “Batteries-included” security: Built-in protections against OWASP Top 10 risks (CSRF, XSS, SQLi)

• Automatic escaping in templates (no |safe = no XSS)

• ORM prevents SQL injection by default

• Clickjacking/XSS/CSRF middleware enabled by default

Weaknesses:

• Complex settings can lead to misconfigurations (e.g., DEBUG=True in production)

• Monolithic design increases attack surface

Key security features:

• django-admin startproject enables security middleware by default

• Password hashing (PBKDF2/Argon2) built-in

• Official Security Docs

2. Flask

Security strengths:

• Minimalist core = smaller attack surface

• Explicit security controls (no “magic”)

Weaknesses:

• No built-in protections: CSRF, SQLi, and XSS rely on extensions

• Template escaping requires MarkupSafe or manual escape()

• Easy to misconfigure (e.g., app.secret_key hardcoded)

Key security features:

• flask-talisman for HTTPS/CSP headers

• flask-seasurf for CSRF protection

• Flask Security Checklist

3. FastAPI

Security strengths:

• Automatic input validation (Pydantic models)

• OAuth2/JWT built-in (via fastapi.security)

• Async reduces thread-based attacks

Weaknesses:

• Dependency injection complexity can introduce risks

• Young ecosystem (fewer battle-tested security extensions)

Key security features:

• SQLAlchemy ORM integration prevents SQLi

• uvicorn with –ssl-keyfile for HTTPS

• Security Docs

4. Pyramid

Security strengths:

• Flexible auth (ACL-based permissions)

• Less magic = fewer hidden attack vectors

Weaknesses:

• Steeper learning curve for security controls

• Smaller community = slower CVE patches

Key security features:

• pyramid_debugtoolbar for dev-time checks

• pyramid_jwt for stateless auth

Critical security comparison¶

Framework-specific threats¶

Django:

• Misconfigured ALLOWED_HOSTS → header injection

• pickle serialization risks in caching

Flask:

• app.debug=True leaks stack traces

• Unsafe jsonify() with user input

FastAPI:

• Dependency injection abuse

• OpenAPI/Swagger exposure in prod

Pyramid:

• Complex ACL rules → permission errors

• Less auto-escaping in templates

Universal Python risks¶

• Dependency hijacking (PyPI malware) → Use pip-audit

• WSGI servers (gunicorn/uWSGI) need hardening

• Secret management (avoid .env files in prod)

Recommendations¶

• Enterprise apps: Django (batteries-included security)

• Microservices: FastAPI (async + Pydantic validation)

• Prototyping: Flask (but add security extensions)

• Flexibility needed: Pyramid (for custom auth)

All frameworks require:

• Content-Security-Policy headers

• Regular safety check scans

• HTTPS enforcement (redirect HTTP → HTTPS)

Tools for hardening¶

• Django: django-security (middleware package)

• Flask: flask-seasurf (CSRF), flask-talisman (CSP)

• FastAPI: secure (headers middleware)

• All: bandit (static analysis), safety (vuln scans)

More¶

• OWASP Python Security Project - PySec

• PyPI Safety Checks