HTTP/2 Rapid Reset: deconstructing the record-breaking attack
Oct 10, 2023Lucas Pardue, Julien Desgats
Summary
This post details the HTTP/2 Rapid Reset attack (CVE-2023-44487), a novel DDoS vector that exploits the HTTP/2 protocol's RST stream mechanism to generate massive request volumes with minimal botnet resources. It explains the HTTP/1.1 and HTTP/2 protocols, the stream lifecycle, and how the RST_STREAM frame can be abused. Cloudflare's mitigation strategies, including automated DDoS system enhancements and coordinated disclosure with Google and AWS, are discussed. The post also provides technical details on the attack's mechanics and the protocol features exploited.
More from the Website Security & Threat Management trail
- We tested our own WAF with frontier AI models. Here’s what we found
- When scanners miss the attack: how Cloudflare Client-Side Security protects storefronts
- Introducing automatic remediation policies with Cloudflare CASB
- Introducing context-aware vulnerability discovery and remediation with Cloudflare Managed Defense and OpenAI Daybreak Models
- Introducing Adaptive Intelligence: undermining the economics of every bot attack