On Monday 2 December 2024 at 10:31 UTC, a TLS handshake exhaustion targeted a airline booking customer in Central Europe. The attack peaked at 58.2 million requests per second and lasted 40 minutes. Traffic originated from 566 autonomous systems in 22 countries, predominantly mobile carrier ranges.
| Vector | TLS handshake exhaustion |
| Peak | 58.2 million requests per second |
| Duration | 40 min |
| Time to mitigation | 0.887 s |
| Attack traffic reaching origin | 0.050% |
| Legitimate traffic challenged | 0.59% |
Timeline
The attack was preceded by no stated motive. Request rates on the targeted routes exceeded their hourly baseline by a factor of 118 within 18 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
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.
Thanks — sharing this with our on-call team.
Could you share the dataset behind the percentages?
Machine-readable ranges are at /ips.json and via the API.
Do you publish the edge IP ranges in a machine-readable format?