CRLF Injection: How a Simple Bug Can Earn You $1500!

Imagine this: You’re casually testing a website, you find a small vulnerability, report it, and boom — you get paid $1500! Sounds too good to be true? Well, welcome to the world of CRLF Injection. This seemingly simple vulnerability can lead to serious security issues like HTTP response splitting, web cache poisoning, and even cross-site scripting (XSS).

In this blog, we’ll break down what CRLF Injection is, how it works, real-world examples, and most importantly — how you can earn bug bounty rewards from it! 🔥

CRLF stands for Carriage Return (\r) and Line Feed (\n) — special characters used to indicate a new line in text files. In web applications, these characters are used in HTTP headers to separate different parts of a response.

A CRLF Injection occurs when an attacker is able to inject these characters into a web application’s HTTP response. This can be dangerous because it allows an attacker to manipulate HTTP headers and control responses in ways that developers never intended.