On Sunday 30 May 2021 at 00:04 UTC, a carpet-bombing UDP flood targeted a B2B SaaS customer in Southeast Asia. The attack peaked at 109.4 Gbps and lasted 45 minutes. Traffic originated from 1727 autonomous systems in 29 countries, predominantly mobile carrier ranges.
| Vector | carpet-bombing UDP flood |
| Peak | 109.4 Gbps |
| Duration | 45 min |
| Time to mitigation | 0.471 s |
| Attack traffic reaching origin | 0.047% |
| Legitimate traffic challenged | 0.05% |
Timeline
The attack was preceded by a breaking political story. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 39 points of presence.
What the customer saw
Checkout conversion was unchanged compared with the same hour of the previous week.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Interesting that most attacks are under ten minutes. Our experience is similar.
This matches what we see in iGaming around big matches.
Verified good bots and allow-listed partners bypass challenges entirely.
Any plans to support per-tenant limits keyed on a JWT claim?
Do you publish the edge IP ranges in a machine-readable format?
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.