CVE-2017-2624

Name	CVE-2017-2624
Description	It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies. If the cookie is correct, it is allowed to attach to the Xorg session. Since most memcmp() implementations return after an invalid byte is seen, this causes a time difference between a valid and invalid byte, which could allow an efficient brute force attack.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-1186-1
Debian Bugs	856398

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
xorg-server (PTS)	bullseye	2:1.20.11-1+deb11u13	fixed
	bullseye (security)	2:1.20.11-1+deb11u14	fixed
	bookworm, bookworm (security)	2:21.1.7-3+deb12u8	fixed
	sid, trixie	2:21.1.15-2	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
xorg-server	source	wheezy	2:1.12.4-6+deb7u8		DLA-1186-1
xorg-server	source	jessie	2:1.16.4-1+deb8u2
xorg-server	source	(unstable)	2:1.19.2-1	low		856398

https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/