CVE-2022-4283

Name	CVE-2022-4283
Description	A vulnerability was found in X.Org. This issue occurs because the XkbCopyNames function leaves a dangling pointer to freed memory, resulting in out-of-bounds memory access on subsequent XkbGetKbdByName requests. This flaw can lead to local privilege elevation on systems where the X server runs privileged and remote code execution for ssh X forwarding sessions.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)
References	DLA-3256-1, DSA-5304-1
Debian Bugs	1026071

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
xorg-server (PTS)	buster	2:1.20.4-1+deb10u4	vulnerable
	buster (security)	2:1.20.4-1+deb10u7	fixed
	bullseye	2:1.20.11-1+deb11u3	vulnerable
	bullseye (security)	2:1.20.11-1+deb11u4	fixed
	bookworm, sid	2:21.1.6-1	fixed
xwayland (PTS)	bookworm, sid	2:22.1.7-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin	Debian Bugs
xorg-server	source	buster	2:1.20.4-1+deb10u7	DLA-3256-1
xorg-server	source	bullseye	2:1.20.11-1+deb11u4	DSA-5304-1
xorg-server	source	(unstable)	2:21.1.5-1		1026071
xwayland	source	(unstable)	2:22.1.6-1

Notes

https://lists.x.org/archives/xorg-announce/2022-December/003302.html
https://gitlab.freedesktop.org/xorg/xserver/commit/ccdd431cd8f1cabae9d744f0514b6533c438908c