CVEs-PoC/2020/CVE-2020-11080.md

CVE-2020-11080

Description

In nghttp2 before version 1.41.0, the overly large HTTP/2 SETTINGS frame payload causes denial of service. The proof of concept attack involves a malicious client constructing a SETTINGS frame with a length of 14,400 bytes (2400 individual settings entries) over and over again. The attack causes the CPU to spike at 100%. nghttp2 v1.41.0 fixes this vulnerability. There is a workaround to this vulnerability. Implement nghttp2_on_frame_recv_callback callback, and if received frame is SETTINGS frame and the number of settings entries are large (e.g., > 32), then drop the connection.

POC

Reference

• https://github.com/nghttp2/nghttp2/security/advisories/GHSA-q5wr-xfw9-q7xr
• https://lists.debian.org/debian-lts-announce/2021/10/msg00011.html
• https://www.oracle.com//security-alerts/cpujul2021.html
• https://www.oracle.com/security-alerts/cpuapr2022.html
• https://www.oracle.com/security-alerts/cpujan2021.html
• https://www.oracle.com/security-alerts/cpujul2020.html
• https://www.oracle.com/security-alerts/cpuoct2020.html

Github

• https://github.com/Live-Hack-CVE/CVE-2020-11080