Amazon Linux AMI Security Advisory: ALAS-2020-1404
Advisory Release Date: 2020-07-27 23:18 Pacific
Advisory Updated Date: 2020-07-29 21:38 Pacific
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. (CVE-2020-11080 )
Run yum update nghttp2 to update your system.