CVE-2020-11080

Summary:

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.

Reference Links(if available):

https://github.com/nghttp2/nghttp2/commit/f8da73bd042f810f34d19f9eae02b46d870af394

https://github.com/nghttp2/nghttp2/security/advisories/GHSA-q5wr-xfw9-q7xr

https://github.com/nghttp2/nghttp2/commit/336a98feb0d56b9ac54e12736b18785c27f75090

https://www.debian.org/security/2020/dsa-4696

http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00024.html

CVSS Score (if available)

v2: / MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P

v3: / HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Links to Exploits(if available)