CVE-2017-2624

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.

Affected

Xorg · xorg-x11-server

CVSS v3.0 NVD

7.0 HIGHCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.0 REDHAT

5.9 MEDIUMCVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

CVSS v2.0 NVD

1.9 LOWAV:L/AC:M/Au:N/C:P/I:N/A:N

EPSS

0.70% chance of exploitation in the next 30 days, 52nd percentile

Published

2018-07-27

Updated

2024-08-05

Proof-of-concept exploits (1)

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

Security advisories

• http://www.securityfocus.com/bid/96480
• http://www.securitytracker.com/id/1037919
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2624
• https://gitlab.freedesktop.org/xorg/xserver/commit/d7ac755f0b618eb1259d93c8a16ec6e39a1862…
• https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
• https://security.gentoo.org/glsa/201704-03
• https://security.gentoo.org/glsa/201710-30
• https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg

References

• CVE Record
• NVD entry