Amazon Linux AMI Security Advisory: ALAS-2021-1517
Advisory Release Date: 2021-07-08 18:38 Pacific
Advisory Updated Date: 2021-07-12 21:51 Pacific
A missing validation flaw was found in libX11. This flaw allows an attacker to inject X11 protocol commands on X clients, and in some cases, also bypass, authenticate (via injection of control characters), or potentially execute arbitrary code with permissions of the application compiled with libX11. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2021-31535)
Run yum update libX11 to update your system.