CVE catalog
CVE-2020-27837
gdm3: CVE-2020-27837
- Severity
- Low · CVSS 3.1
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.23% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | gdm3 | sid | 51.1-1 | fixed |
| Debian | gdm3 | forky | 51.1-1 | fixed |
| Debian | gdm3 | trixie | 48.0-2 | fixed |
| Debian | gdm3 | bookworm | 43.0-3 | fixed |
| Ubuntu | gdm3 | 20.04 | 3.34.1-1ubuntu1 | vulnerable |
| Ubuntu | gdm3 | 20.04 | 3.36.3-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | gdm3 | 20.04 | 3.36.3-0ubuntu0.20.04.2 | vulnerable |
| Ubuntu | gdm3 | 20.04 | 3.36.3-0ubuntu0.20.04.3 | vulnerable |
| Ubuntu | gdm3 | 20.04 | 3.36.3-0ubuntu0.20.04.4 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 41~rc-0ubuntu2 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 41.0-3ubuntu1 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 41.0-3ubuntu2 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 41.3-1ubuntu1 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 41.3-1ubuntu2 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 41.3-1ubuntu3 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu1 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu2 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu4 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu6 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu7 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu7.22.04.1 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu7.22.04.2 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu7.22.04.3 | vulnerable |
| Ubuntu | gdm3 | 22.04 | 42.0-1ubuntu7.22.04.4 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | gdm3 | source | sid | 3.38.2.1-1 | not yet assigned | Not reported | Not reported |
| Debian | gdm3 | source | forky | 3.38.2.1-1 | not yet assigned | Not reported | Not reported |
| Debian | gdm3 | source | trixie | 3.38.2.1-1 | not yet assigned | Not reported | Not reported |
| Debian | gdm3 | source | bookworm | 3.38.2.1-1 | not yet assigned | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [gdm3]Fixed
Details (2)
43.0-3· amd64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
43.0-3· arm64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
- [gir1.2-gdm-1.0]Fixed
Source package: [gdm3]
Details (2)
43.0-3· amd64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
43.0-3· arm64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
- [libgdm1]Fixed
Source package: [gdm3]
Details (2)
43.0-3· amd64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
43.0-3· arm64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
- [libgdm-dev]Fixed
Source package: [gdm3]
Details (2)
43.0-3· amd64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
43.0-3· arm64 · bookwormFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · bookworm; dsa · gdm3 · debian · 12
[Debian 13 (Trixie)]
- [gdm3]Fixed
Details (2)
48.0-2· amd64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
48.0-2· arm64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
- [gir1.2-gdm-1.0]Fixed
Source package: [gdm3]
Details (2)
48.0-2· amd64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
48.0-2· arm64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
- [libgdm1]Fixed
Source package: [gdm3]
Details (2)
48.0-2· amd64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
48.0-2· arm64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
- [libgdm-dev]Fixed
Source package: [gdm3]
Details (2)
48.0-2· amd64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
48.0-2· arm64 · trixieFixed · Fixed:
3.38.2.1-1dsa · gdm3 · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2024_11547-1.json]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2020-27837]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2020-27837]
- [https://security-tracker.debian.org/tracker/CVE-2020-27837]
[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]