CVE-2020-27837

Severity: medium (CVSS 6.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-12-28 · updated 2026-06-17
Weakness: CWE-362

Description

A flaw was found in GDM in versions prior to 3.38.2.1. A race condition in the handling of session shutdown makes it possible to bypass the lock screen for a user that has autologin enabled, accessing their session without authentication. This is similar to CVE-2017-12164, but requires more difficult conditions to exploit.

Affected products

Gnome Display Manager: before 3.38.2.1 — fixed in 3.38.2.1

How to fix

Upgrade to a fixed version: Gnome Display Manager 3.38.2.1. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1906812
https://bugzilla.redhat.com/show_bug.cgi?id=1906812

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