On Friday 21 January 2022 at 19:58 UTC, a cache-busting query flood targeted a developer platform customer in Central Europe. The attack peaked at 764.4 million requests per second and lasted 110 minutes. Traffic originated from 1973 autonomous systems in 20 countries, predominantly compromised cloud VMs.
| Vector | cache-busting query flood |
| Peak | 764.4 million requests per second |
| Duration | 110 min |
| Time to mitigation | 0.920 s |
| Attack traffic reaching origin | 0.065% |
| Legitimate traffic challenged | 0.66% |
Timeline
The attack was preceded by no stated motive. Request rates on the targeted routes exceeded their hourly baseline by a factor of 455 within 5 seconds. The risk score of participating clients crossed the challenge threshold automatically and proof-of-work difficulty rose with origin load.
What the customer saw
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Add a dedicated rate limit for the targeted route.
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
We moved from a scrubbing provider to always-on last year; time to mitigation went from minutes to basically nothing.
Great to hear, thanks for sharing your experience.
Do you publish the edge IP ranges in a machine-readable format?