CVE-2017-12164 Auth bypass in gdm
Attackers can bypass screen lock and gain user access if autologin is enabled, due to a missing state check in GDM.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2017-12164?
CVE-2017-12164 is a medium-severity authentication bypass vulnerability in GNOME gdm, published on 26 Jul 2018. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
A flaw was discovered in gdm 3.24.1 where gdm greeter was no longer setting the ran_once boolean during autologin. If autologin was enabled for a victim, an attacker could simply select 'login as another user' to unlock their screen.
Which versions are affected by CVE-2017-12164?
It affects 1 product.
Products include Gnome Gnome Display Manager.
How do I fix CVE-2017-12164?
Apply the vendor's patch.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2017-12164 being exploited?
There is no known exploitation of CVE-2017-12164 in the wild and no public exploit code.
Other vulnerabilities in GNOME gdm
Sources
Also known as DEBIAN-CVE-2017-12164, GHSA-87vr-968r-r3qp, MGASA-2018-0056.