Gnome Display ManagerApplication · Gnome

CVE-2018-14424

HIGH · 7.8 CVSS v3.0 Published 2018-08-14
Fix available
A fix is available. Upgrade to after 3.29.1 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The daemon in GDM through 3.29.1 does not properly unexport display objects from its D-Bus interface when they are destroyed, which allows a local attacker to trigger a use-after-free via a specially crafted sequence of D-Bus method calls, resulting in a denial of service or potential code execution.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

GDM (GNOME Display Manager) through version 3.29.1 contains a use-after-free vulnerability in its D-Bus daemon interface. When display objects are destroyed, the daemon fails to properly unexport them from the D-Bus interface, leaving dangling references. A local attacker can exploit this by issuing a crafted sequence of D-Bus method calls to trigger the use-after-free, potentially achieving code execution with GDM privileges.

MitigationUpgrade GDM to version 3.29.2 or later, which contains the fix for proper object lifecycle management in the D-Bus interface. As a defensive measure, restrict local untrusted user access to the system.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Gnome Display ManagerApplication
Affected:<= 3.29.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if GDM is installed
    Run 'rpm -q gdm' (RHEL/Fedora) or 'dpkg -l gdm' (Debian/Ubuntu) or 'gdm --version' to see if GNOME Display Manager is present on the system
    Affected if GDM is not installed, the system is not affected by this specific vulnerability
  2. Determine the installed GDM version
    Run 'gdm --version' or check the package manager output (rpm -qi gdm / dpkg -s gdm) to obtain the exact version number
    Affected if The installed version is 3.29.1 or lower, placing it within the affected range (<= 3.29.1)
  3. Verify D-Bus interface for GDM is enabled
    Check if the GDM D-Bus service is active by running 'busctl list' or looking for 'org.gnome.DisplayManager' in the D-Bus services (typically at /usr/share/dbus-1/interfaces/ or via 'gdbus introspect')
    Affected if The D-Bus interface for GDM is enabled and exposed, which is required for the vulnerability to be exploitable
  4. Check for dangling D-Bus object references
    Monitor D-Bus traffic using 'dbus-monitor' or review system logs for any use-after-free errors or crashes related to GDM's display object lifecycle
    Affected if There are signs of improper object cleanup, unexport failures, or GDM crashes during D-Bus operations, indicating the vulnerable code path may be triggered

A system is affected if GDM version 3.29.1 or lower is installed and the D-Bus interface is enabled, allowing a local attacker to trigger the use-after-free through crafted D-Bus method calls.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 3.29.1
Interim mitigation

Upgrade GDM to version 3.29.2 or later, which contains the fix for proper object lifecycle management in the D-Bus interface. As a defensive measure, restrict local untrusted user access to the system.

Fix this in Gnome Display Manager Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,000
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-14424 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data