How severe is CVE-2020-27837?

CVE-2020-27837 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-27837 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27837?

CVE-2020-27837 affects Gnome Gnome Display Manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27837?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-27837 published?

CVE-2020-27837 was published on 2020-12-28 and last updated on 2026-06-17.

CVE-2020-27837

CVE-2020-27837 is a medium-severity vulnerability in Gnome Gnome Display Manager with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
CVSS v2: 4.4
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Gnome Gnome Display Manager
Published: 2020-12-28
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-27837?: 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.
How severe is CVE-2020-27837?: CVE-2020-27837 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-27837 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27837?: CVE-2020-27837 affects Gnome Gnome Display Manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27837?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-27837 published?: CVE-2020-27837 was published on 2020-12-28 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:gnome:gnome_display_manager:*:*:*:*:*:*:*:*

More vulnerabilities in Gnome Gnome Display Manager

CVE-2018-14424 — High (CVSS 7.8): The daemon in GDM through 3.29.1 does not properly unexport display objects from its D-Bus interface when they are…
CVE-2020-16125 — High (CVSS 7.2): gdm3 versions before 3.36.2 or 3.38.2 would start gnome-initial-setup if gdm3 can't contact the accountservice service…
CVE-2015-7496 — High (CVSS 7.2): GNOME Display Manager (gdm) before 3.18.2 allows physically proximate attackers to bypass the lock screen by holding…
CVE-2013-4169 — Medium (CVSS 6.9): GNOME Display Manager (gdm) before 2.21.1 allows local users to change permissions of arbitrary directories via a…
CVE-2019-3825 — Medium (CVSS 6.3): A vulnerability was discovered in gdm before 3.31.4. When timed login is enabled in configuration, an attacker could…
CVE-2017-12164 — Medium (CVSS 4.1): A flaw was discovered in gdm 3.24.1 where gdm greeter was no longer setting the ran_once boolean during autologin. If…

All CVEs affecting Gnome Gnome Display Manager →

Other CWE-362 (Race Condition) vulnerabilities

CVE-2022-27626 — Critical (CVSS 10.0): A vulnerability regarding concurrent execution using shared resource with improper synchronization ('Race Condition')…
CVE-2015-8556 — Critical (CVSS 10.0): Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.
CVE-2014-0703 — Critical (CVSS 10.0): Cisco Wireless LAN Controller (WLC) devices 7.4 before 7.4.110.0 distribute Aironet IOS software with a race condition…
CVE-2010-1228 — Critical (CVSS 10.0): Multiple race conditions in the sandbox infrastructure in Google Chrome before 4.1.249.1036 have unspecified impact and…
CVE-2008-6598 — Critical (CVSS 10.0): Multiple race conditions in WANPIPE before 3.3.6 have unknown impact and attack vectors related to "bri restart logic."
CVE-2026-46137 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: fix potential…

Browse all CWE-362 (Race Condition) vulnerabilities →