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How I Made $6,000 by Exploiting JWT Manipulation on a Web3 Crypto App 💰💻
🔥 The $6,000 Bug Bounty Story
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A few months ago, while hunting for vulnerabilities in Web3 applications, I stumbled upon a critical JWT (JSON Web Token) manipulation bug that led to a $6,000 bounty payout! 🚀 If you’re into bug bounty hunting, cybersecurity, or Web3 security, you’ll love this breakdown of how I found, exploited, and reported this issue.
🧐 What is JWT and Why Does It Matter?
JWT (JSON Web Token) is widely used for authentication in Web3 and traditional web applications. It’s a compact, URL-safe token that stores claims between parties. A typical JWT looks like this:
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoxMjM0NTYsImFkbWluIjpmYWxzZX0.7QDfCe1D7sPdX9Dg3pYMLkx_1J1G
This token has three parts:
- Header — Contains the algorithm and token type.
- Payload — Contains the claims (e.g., user ID, roles).
- Signature — Ensures the token’s integrity.
When implemented correctly, JWT ensures secure authentication. However, misconfigurations can make it a hacker’s playground. 🎯