X.Org server security advisory: April 13, 2021

[Matthieu Herrb]

X.Org server security advisory: April 13, 2021


Input validation failures in X server XInput extension
======================================================


Insufficient checks on the lengths of the XInput extension
ChangeFeedbackControl request can lead to out of bounds memory
accesses in the X server.

These issues can lead to privilege escalation for authorized clients
on systems where the X server is running privileged.

* CVE-2021-3472 / ZDI CAN 12549 XChangeFeedbackControl Integer Underflow

Patch
-----

A patch for this issue has been committed to the xorg server git
repository. xorg-server 1.20.11 and xwayland 21.1.1 will be released
shortly and will include this patch.

https://gitlab.freedesktop.org/xorg/xserver.git

commit 7aaf54a1884f71dc363f0b884e57bcb67407a6cd

Fix XChangeFeedbackControl() request underflow

CVE-2021-3472 / ZDI-CAN-1259

Thanks
======

These vulnerabilities have been discovered by Jan-Niklas Sohn working
with Trend Micro Zero Day Initiative.