An AI Agent Cracked a Live Login System. The Hard Part Came Next.
Michael Miller ·
Listen to this article~3 min
An AI agent found a critical OTP bypass on a live insurer's site. The bug was simple. Proving it in production was the real challenge.
The bug was almost laughably simple: the login page let you choose where your sign-in code went. Proving it on a live website? That was the hard part.
### What Actually Happened
During an authorized assessment, an AI pentesting agent found a critical authentication bypass on a major insurer's production website. On its own. No hand-holding, no human nudging it toward the answer.
One login request let the user decide where the one-time passcode (OTP) was delivered. That's it. That's the whole vulnerability.
Sounds small, right? It isn't. If you can redirect where an OTP lands, you can often redirect it straight into your own hands. Game over.
### The Attack Was the Easy Part
Here's the thing nobody tells you about security work. Finding the flaw is often the simplest step. Proving it in a live, messy, real-world environment is where things get brutal.
A production system isn't a lab. It's full of rate limits, logging, monitoring, and a whole lot of people watching. You can't just fire off a request and hope for the best.
- You have to confirm the bug exists without breaking anything.
- You have to document it in a way that survives scrutiny.
- You have to show impact, not just theory.
That gap between "I found something" and "I proved something" is where most findings die.
### Why This Matters for Anyone Running a Browser
If you're in the antidetect browser world, this story should hit close to home. Most of us juggle dozens of accounts, sessions, and logins every day. And OTP flows are everywhere.
When a login lets the user pick the delivery channel, that's a design choice, not a bug on its own. The bug shows up when that choice isn't locked down.
> A one-time passcode is only as strong as the path it travels. Open the path, and you've opened the door.
So what do you actually do about it?
- Audit every login flow you rely on. Don't assume the platform got it right.
- Treat OTP delivery as a security boundary, not a convenience feature.
- Keep your sessions isolated. A clean browser profile won't save you if the auth layer is broken.
### The Bigger Lesson
AI agents are getting good at finding these cracks. That's not a scare tactic. It's just where things are heading. The real skill isn't spotting the flaw. It's proving it, explaining it, and fixing it before someone with worse intentions does.
The attack was the easy part. Everything after is the job.
