Post Syndicated from original https://lwn.net/Articles/927887/

The X.Org project has announced a vulnerability in its X server and Xwayland (CVE-2023-1393).

This issue can lead to local privileges elevation on systems where the X
server is running privileged and remote code execution for ssh X forwarding
sessions.

[…] If a client explicitly destroys the compositor overlay window (aka COW),
the Xserver would leave a dangling pointer to that window in the CompScreen
structure, which will trigger a use-after-free later.

That has led to the release of xorg-server 21.1.8, xwayland 22.1.9, and xwayland 23.1.1.