CVE-2017-2624 Information disclosure in xorg-x11-server
Timing side-channel in Xorg MIT cookie validation allows efficient brute-force attacks to hijack X11 sessions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-2624?
CVE-2017-2624 is a medium-severity vulnerability in Debian Debian Linux, published on 27 Jul 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2017-2624?
It affects 2 products.
Linux distribution packages (5)
xorg-x11-server SUSE:Linux Enterprise Desktop 12 SP2 | All versions | 7.6_1.18.3-71.1 |
xorg-x11-server SUSE:Linux Enterprise Server 12 SP2 | All versions | 7.6_1.18.3-71.1 |
xorg-x11-server SUSE:Linux Enterprise Server for Raspberry Pi 12 SP2 | All versions | 7.6_1.18.3-71.1 |
xorg-x11-server SUSE:Linux Enterprise Server for SAP Applications 12 SP2 | All versions | 7.6_1.18.3-71.1 |
xorg-x11-server SUSE:Linux Enterprise Software Development Kit 12 SP2 | All versions | 7.6_1.18.3-71.1 |
Products include Debian Debian Linux, X.org X Server.
How do I fix CVE-2017-2624?
Upgrade to a fixed version.
Is CVE-2017-2624 being exploited?
There is no known exploitation of CVE-2017-2624 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2017-2624, GHSA-6pw7-qhf8-rjff, MGASA-2018-0200, SUSE-SU-2017:1675-1, UBUNTU-CVE-2017-2624.