During a comprehensive security audit of three web applications, critical vulnerabilities in JSON Web Token (JWT) implementation were identified. These vulnerabilities expose significant security risks that could allow unauthorized access, token manipulation, and potential system compromise. JWT Security Vulnerabilities Lab Overview This repository contains a series of Flask-based web applications demonstrating common JSON Web Token (JWT) security vulnerabilities. The lab is designed to educate developers and security professionals about potential weaknesses in JWT implementation. 🚨 Important Security Warning CAUTION: These applications are intentionally vulnerable and should ONLY be used in controlled, educational environments. Do NOT deploy these applications in any production or public-facing setting. Vulnerability Demonstrations Lab 1: JWT None Algorithm Vulnerability
Vulnerability Type: Algorithm Manipulation Key Issue: Accepting 'none' algorithm for token verification Risk: Allows token payload modification without signature validation
Lab 2: Weak Secret Key Vulnerability
Vulnerability Type: Cryptographic Weakness Key Issue: Using a trivial, easily guessable secret key Risk: Enables token forgery through brute-force techniques
Lab 3: Missing Signature Verification
Vulnerability Type: Token Validation Bypass Key Issue: Manual token parsing without cryptographic verification Risk: Permits arbitrary token payload manipulation
Prerequisites
Python 3.8+ Flask PyJWT Base64
Installation
Clone the repository
bashgit clone https://github.com/yourusername/jwt-vulnerabilities-lab.git cd jwt-vulnerabilities-lab
Create a virtual environment
bashpython3 -m venv venv
source venv/bin/activate # On Windows, use venv\Scripts\activate
Install dependencies
bashpip install flask pyjwt Running the Labs Lab 1: None Algorithm Vulnerability bashpython lab01_app.py
Runs on http://localhost:5001
Lab 2: Weak Secret Key Vulnerability bashpython lab02_app.py
Runs on http://localhost:5000
Lab 3: Missing Signature Verification bashpython lab03_app.py
Runs on http://localhost:5003
Learning Objectives
Understand common JWT security vulnerabilities Learn how improper token validation can lead to security breaches Develop skills in identifying and mitigating JWT-related risks
Recommended Countermeasures
Always verify token signatures Use strong, randomly generated secret keys Explicitly specify allowed algorithms Implement robust token validation Use short-lived tokens Implement additional authentication layers
Ethical Use Statement This lab is intended for educational purposes only. It is designed to:
Increase awareness of JWT security vulnerabilities Train security professionals and developers Demonstrate the importance of secure token implementation
Security Best Practices
Never use these exact implementations in production Regularly update and patch authentication mechanisms Conduct thorough security audits Stay informed about the latest security vulnerabilities
Contributing Contributions, improvements, and additional vulnerability demonstrations are welcome! Please:
Fork the repository Create your feature branch (git checkout -b feature/AmazingSecurityDemo) Commit your changes (git commit -m 'Add some security insight') Push to the branch (git push origin feature/AmazingSecurityDemo) Open a Pull Request
License This project is for educational purposes. Please review and comply with all applicable legal and ethical guidelines when using this material. Disclaimer The vulnerabilities demonstrated are real and dangerous. This lab is strictly for educational purposes to help developers understand and prevent such security risks. Additional Resources
OWASP JWT Cheat Sheet JWT.io Security Best Practices
About the Author Created as part of an Ethical Hacking and Cybersecurity Training Program.
🔒 Remember: Security is a continuous learning process!