API Fuzzing for Bug Bounty: Unlock the Secrets of Vulnerable APIs

Introduction

Application Programming Interfaces (APIs) are the backbone of modern web and mobile applications, enabling seamless communication between different systems. However, their complexity and open nature make them prime targets for attackers. API fuzzing, a critical skill for bug bounty hunters, involves injecting unexpected or random data into APIs to discover vulnerabilities. This blog dives deep into API fuzzing, its techniques, tools, and strategies to help bug bounty hunters unlock the secrets of vulnerable APIs.

What is API Fuzzing?

API fuzzing is a security testing method where invalid, unexpected, or random data is sent to an API to identify potential security vulnerabilities, such as crashes, data leaks, and unauthorized access. It helps uncover:

1. Authentication Issues
2. Improper Input Validation
3. Rate Limiting and Throttling Flaws
4. Information Disclosure
5. Business Logic Errors
6. Denial of Service (DoS) Vulnerabilities

Why API Fuzzing is Essential in Bug Bounties

1. API Dominance: APIs account for over 80% of web traffic…