An attacker can make the Node.js HTTP/2 server completely unavailable by sending a small amount of HTTP/2 frames packets with a few HTTP/2 frames inside. It is possible to leave some data in nghttp2 memory after reset when headers with HTTP/2 CONTINUATION frame are sent to the server and then a TCP connection is abruptly closed by the client triggering the Http2Session destructor while header frames are still being processed (and stored in memory) causing a race condition.

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-27983
• https://hackerone.com/reports/2319584
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JDECX4BYZLMM4S4LALN4DPZ2HUTTPLKE
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YDVFUH7ACZPYB3BS4SVILNOY7NQU73VW