HTTP/2 Rapid Reset Zero-Day Vulnerability Exploited to Launch Record DDoS Attacks
Oct 10, 2023
Server Security / Vulnerability
Amazon Web Services (AWS), Cloudflare, and Google on Tuesday said they took steps to mitigate record-breaking distributed denial-of-service (DDoS) attacks that relied on a novel technique called HTTP/2 Rapid Reset. The layer 7 attacks were detected in late August 2023, the companies said in a coordinated disclosure. The cumulative susceptibility to this attack is being tracked as CVE-2023-44487 , and carries a CVSS score of 7.5 out of a maximum of 10. While the attacks aimed at Google's cloud infrastructure peaked at 398 million requests per second (RPS), the ones that struck AWS and Cloudflare exceeded a volume of 155 million and 201 million RPS, respectively. HTTP/2 Rapid Reset refers to a zero-day flaw in the HTTP/2 protocol that can be exploited to carry out DDoS attacks. A significant feature of HTTP/2 is multiplexing requests over a single TCP connection, which manifests in the form of concurrent streams. What's more, a client that wants to abort a request can