Microsoft Response to Distributed Denial of Service (DDoS) Attacks against HTTP/2

Summary Beginning in September 2023, Microsoft was notified by industry partners about a newly identified Distributed Denial-of-Service (DDoS) attack technique being used in the wild targeting HTTP/2 protocol. This vulnerability (CVE-2023-44487) impacts any internet exposed HTTP/2 endpoints. As an industry leader, Microsoft promptly opened an investigation and subsequently began working with industry partners for a coordinated disclosure and mitigation plan.