Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service

Summary

Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.

Timeline

1. Aug 13, 2019, 8:50 PM UTCCVE published
2. Aug 4, 2024, 9:54 PM UTCRecord last updated
3. Oct 28, 2026EPSS reached 10%

   FIRST estimates at least a 10% chance of exploitation in the next 30 days

Affected versions

• n/a n/a

  Version range not reported

References 25