RHSA-2023:5766HighCVSS 7.5

Red Hat Security Advisory: nghttp2 security update

Published
October 17, 2023
Last Modified
August 18, 2026

🔗 CVE IDs covered (1)

CVE-2023-44487 →

📋 Description

CVE-2023-44487 — HTTP/2: Multiple HTTP/2 enabled web servers are vulnerable to a DDoS attack (Rapid Reset Attack)

🎯 Affected products14

  • Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • libnghttp2-0:1.33.0-3.el8_1.2.i686 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • libnghttp2-0:1.33.0-3.el8_1.2.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • libnghttp2-0:1.33.0-3.el8_1.2.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • libnghttp2-debuginfo-0:1.33.0-3.el8_1.2.i686 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • libnghttp2-debuginfo-0:1.33.0-3.el8_1.2.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • libnghttp2-debuginfo-0:1.33.0-3.el8_1.2.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • nghttp2-0:1.33.0-3.el8_1.2.src as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • nghttp2-debuginfo-0:1.33.0-3.el8_1.2.i686 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • nghttp2-debuginfo-0:1.33.0-3.el8_1.2.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • nghttp2-debuginfo-0:1.33.0-3.el8_1.2.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • nghttp2-debugsource-0:1.33.0-3.el8_1.2.i686 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • nghttp2-debugsource-0:1.33.0-3.el8_1.2.ppc64le as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • nghttp2-debugsource-0:1.33.0-3.el8_1.2.x86_64 as a component of Red Hat Enterprise Linux BaseOS E4S (v. 8.1)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: Users are strongly urged to update their software as soon as fixes are available. There are several mitigation approaches for this flaw. 1. If circumstances permit, users may disable http2 endpoints to circumvent the flaw altogether until a fix is available. 2. IP-based blocking or flood protection and rate control tools may be used at network endpoints to filter incoming traffic. 3. Several package specific mitigations are also available. a. nginx: https://www.nginx.com/blog/http-2-rapid-reset-attack-impacting-f5-nginx-products/ b. netty: https://github.com/netty/netty/security/advisories/GHSA-xpw8-rcwv-8f8p c. haproxy: https://www.haproxy.com/blog/haproxy-is-not-affected-by-the-http-2-rapid-reset-attack-cve-2023-44487 d. nghttp2: https://github.com/nghttp2/nghttp2/security/advisories/GHSA-vx74-f528-fxqg e. golang: The default stream concurrency limit in golang is 250 streams (requests) per HTTP/2 connection. This value may be adjusted in the golang.org/x/net/http2 package using the Server.MaxConcurrentStreams setting and the ConfigureServer function which are available in golang.org/x/net/http2.

🔗 References (5)