Turning Security Features Into Attack Vectors Through Creative Abuse
While testing a fintech API last month, I discovered their “robust” rate limiting system had a fatal flaw — it could be tricked into locking every user account for 24 hours. What the developers intended as brute-force protection became a denial-of-service weapon, earning me a $500 bounty. Here’s how API safeguards can backfire spectacularly.
Press enter or click to view image in full size
Modern APIs implement protections like:
- IP-based throttling (100 requests/minute)
- Account lockouts (5 failed logins → 15min freeze)
- CAPTCHAs after suspicious activity
The Irony:
68% of these controls introduce new vulnerabilities when misconfigured (2024 Cloud Security Report)
Phase 1: Normal Testing Hit a Wall
curl -X POST https://api.bank.com/login -d '{"user":"test"}'
# Response: 429 Too Many Requests