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Decoding API Vulnerabilities: My Bug Bounty Saga on API Vulnerabilities
“This is the part 1” and Here is the free link: “https://myselfakash20.medium.com/decoding-api-vulnerabilities-my-bug-bounty-saga-on-api-vulnerabilities-affaf6a7c575?sk=09d95b306648f4a1f35bc555e92f2dd7”
Imagine this: you’re casually exploring an app, dissecting its backend for hidden treasures, and suddenly you stumble upon a gateway to sensitive data. That’s the rush every bug bounty hunter lives for. APIs, the unsung heroes of the tech world, often become the Achilles’ heel of even the most robust systems. They’re like veins pumping data through the internet’s vast body, and when improperly secured, they can expose everything from private user data to entire databases.
As a passionate security researcher with years of bug bounty experience, I specialize in uncovering API vulnerabilities. My journey has been one of curiosity and persistence, fueled by late-night hunts and eureka moments. Through this blog, I’ll take you behind the scenes of one of my most thrilling discoveries, sharing the tools, techniques, and insights that led to an extraordinary payout. This is not just a story — it’s a blueprint for aspiring hunters.
Unmasking the Flaw: The Discovery
While testing a popular e-commerce platform’s API, I noticed an endpoint /api/v1/order/export that allowed users to export their order history as a CSV file. On closer inspection, the user_id parameter was exposed. Curious, I decided to probe further.
Step 1: Reconnaissance with Postman Postman is a go-to tool for API exploration. Using Postman, I sent a GET request with an altered user_id:
GET /api/v1/order/export?user_id=12345 HTTP/1.1
Host: example.com
Authorization: Bearer eyJhbGciOiJI...The response was surprising — it returned order data for a completely different user! This pointed to an Insecure Direct Object Reference (IDOR) vulnerability.
Step 2: Mapping the API Endpoints Using Burp Suite, I intercepted API traffic and generated a map of endpoints. The vulnerable endpoint stood out because it accepted user-modifiable parameters without proper validation.
