Detections
Analytics
CVE-2017-2624
high
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.
References
https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/
https://security.gentoo.org/glsa/201710-30
https://security.gentoo.org/glsa/201704-03
https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
https://gitlab.freedesktop.org/xorg/xserver/commit/d7ac755f0b618eb1259d93c8a16ec6e39a18627c
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2624