Vibecoding Your Way to Remote Code Execution
Vibecoding Your Way to Remote Code Execution
Earlier this week, a colleague introduced me to https://bolt.new — an AI-powered tool that generates fullstack web apps right in your browser.
At first glance, it’s very impressive. You describe what you want, and it scaffolds a project in seconds.
Coincidentally, later that day I saw a Reddit post claiming “soon developers will be out of a job” because of Bolt. Naturally, I had to test that 😅
So I asked Bolt to build a simple file upload site — something non-technical users could use to drop files onto a server, no FTP or SCP needed.
It delivered: clean UI, quick setup. But when I reviewed the code… well…
⚠️ Vulnerability 1: Stored XSS
The Node.js version let me upload .html files and served them directly — no file type filtering, no sanitization.
I uploaded:
<script>alert('XSS??')</script>…and it ran the moment I opened it.
Why this matters:
The alert is just proof of concept. But malicious JavaScript running in a browser could:
Steal session cookies and impersonate users
Redirect to phishing or malware sites
Exfiltrate data from active sessions
🔥 Vulnerability 2: Reverse Shell (PHP edition)
I asked Bolt to create a PHP version — even though it’s JS-native.
This one had:
✅ No MIME type checks
✅ Original filename preserved
✅ Public /uploads directory
✅ move_uploaded_file() and vibes…
So I uploaded a shell.php, opened it in the browser, and…
🎯 Got a shell in my terminal.
Why this matters:
A reverse shell gives full remote control of the server — read/write/delete files, run commands, exfiltrate data, or wipe everything.
🧠 Takeaway
Be careful vibecoding out there. AI-generated code will keep getting better — but so will the risk of dodgy vulnerabilities like these.
🧰 GitHub Demo
You can find a redacted version of the test repo here:👉 https://github.com/Lillevang/bolt-pwn