When Missing Rate Limiting Leads to a Critical Authentication Finding: A Real-World Case Study

Mon, 06 Jul 2026 00:00:00 +0000

Hey It’s been quite a while since my last article, but I’m excited to start publishing consistently again, covering web application security, bug bounty research, CTFs, penetration testing, and the lessons I learn along the way.

Let’s start with one of the most interesting authentication issues I’ve ever reported.

So, let’s talk about the critical vulnerability I found in what we’ll call example.com

I started by testing the login functionality of the main application. Since I had only discovered the login page about 10 minutes earlier, I simply began interacting with it, clicking through the functionality and looking for anything interesting.

Markdown on idkwhoiamx999

When Missing Rate Limiting Leads to a Critical Authentication Finding: A Real-World Case Study