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Fencer Vulns
high 7.2

CVE-2020-16125 json

gdm3 would start gnome-initial-setup if it cannot contact accountservice

published 2020-11-10 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-8091

cvss
7.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

gdm3 versions before 3.36.2 or 3.38.2 would start gnome-initial-setup if gdm3 can't contact the accountservice service via dbus in a timely manner; on Ubuntu (and potentially derivatives) this could be be chained with an additional issue that could allow a local user to create a new privileged account.

Patch / fix

  • Gnome GDM3 3.36.4, 3.38.2
  • gdm3 Debian 14, Debian 13, Debian 12 3.38.2-1

debian advisories DEBIAN-CVE-2020-16125

  • gdm3 Ubuntu 18.04 LTS 3.28.3-0ubuntu18.04.6
  • gdm3 Ubuntu 20.04 LTS 3.36.3-0ubuntu0.20.04.2

ubuntu advisories UBUNTU-CVE-2020-16125

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • gdm RHEL 8 1:3.28.3-39.el8
  • glib2 RHEL 8 2.56.4-9.el8
  • glib2-fam RHEL 8 2.56.4-9.el8
  • glib2-tests RHEL 8 2.56.4-9.el8
  • webkit2gtk3 RHEL 8 2.30.4-1.el8
  • webkit2gtk3-jsc RHEL 8 2.30.4-1.el8

red hat advisories RHSA-2021:1586

  • gdm SLE Module for Desktop Applications 15 SP1 3.26.2.1-13.39.2
  • gdm SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +15 more 3.10.0.1-54.17.2
  • gdm SLE Module for Desktop Applications 15 SP2 3.34.1-8.9.1

suse advisories SUSE-SU-2020:3799-1SUSE-SU-2020:3614-1SUSE-SU-2020:3333-1

  • gdm openSUSE Tumbleweed 41.0-1.1
  • gdm openSUSE Leap 15.1 3.26.2.1-lp151.16.10.1
  • gdm openSUSE Leap 15.2 3.34.1-lp152.6.9.1

opensuse advisories openSUSE-SU-2024:11547-1openSUSE-SU-2020:2264-1openSUSE-SU-2020:1961-1

  • gjs AlmaLinux 8 1.56.2-5.el8
  • gtk2 AlmaLinux 8 2.24.32-5.el8
  • gvfs AlmaLinux 8 1.36.2-11.el8
  • vala AlmaLinux 8 0.40.19-2.el8
  • atkmm AlmaLinux 8 2.24.2-7.el8
  • gamin AlmaLinux 8 0.1.10-32.el8
  • woff2 AlmaLinux 8 1.0.2-5.el8
  • cairomm AlmaLinux 8 1.12.0-8.el8

almalinux advisories ALSA-2021:1586

  • gdm Rocky Linux 8 1:3.28.3-39.el8
  • gjs Rocky Linux 8 1.56.2-5.el8
  • gtk2 Rocky Linux 8 2.24.32-5.el8
  • gvfs Rocky Linux 8 1.36.2-11.el8
  • vala Rocky Linux 8 0.40.19-2.el8
  • atkmm Rocky Linux 8 2.24.2-7.el8
  • gamin Rocky Linux 8 0.1.10-32.el8
  • woff2 Rocky Linux 8 1.0.2-5.el8

rocky linux advisories RLSA-2021:1586

  • gdm Arch Linux 3.38.2-1

arch linux advisories AVG-1264

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-16125 updated cvss 6.4

gdm: inability to timely contact accountservice via dbus leads gnome-initial-setup to creation of account with admin privileges

  • Red Hat Enterprise Linux 5 gdm Red Hat Enterprise Linux 6 gdm, gdm-libs, gdm-plugin-smartcard, gdm-plugin-fingerprint, gdm-user-switch-applet Red Hat Enterprise Linux 7 gdm
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) gdm 3.28.3-39.el8
    fixed: vendor fix RHSA-2021:1586
  • Red Hat CodeReady Linux Builder (v. 8) gvfs 1.36.2-11.el8, vala 0.40.19-2.el8, libsass 3.4.5-6.el8, libdazzle 3.28.5-2.el8, libepubgen 0.1.0-3.el8, nautilus 3.28.1-15.el8 Red Hat Enterprise Linux 9 gdm Red Hat Enterprise Linux AppStream (v. 8) gjs 1.56.2-5.el8, woff2 1.0.2-5.el8, atkmm 2.24.2-7.el8, gtk2 2.24.32-5.el8, gvfs 1.36.2-11.el8, cairomm 1.12.0-8.el8, +72 more Red Hat Enterprise Linux BaseOS (v. 8) glib2 2.56.4-9.el8, gamin 0.1.10-32.el8, glib2-fam 2.56.4-9.el8, glib2-tests 2.56.4-9.el8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.11% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gitlab.gnome.org https://gitlab.gnome.org/GNOME/gdm/-/issues/642 referenced PoC, tagged "exploit" by a source, unverified
  • securitylab.github.com https://securitylab.github.com/advisories/GHSL-2020-202-gdm3-LPE-unresponsive-accounts-daemon referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.2 CVSS:3.1/AV:P/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
NVD 3.1 6.8 CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Gnome GDM3

Classification

Weakness
  • CWE-754 Improper Check for Unusual or Exceptional Conditions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.