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FedoraOperating system · Fedoraproject

CVE-2023-0494

HIGH · 7.8 CVSS v3.1 Published 2023-03-27
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
80/100
Remediation priority · High
Zero-click Patch available

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
A vulnerability was found in X.Org. This issue occurs due to a dangling pointer in DeepCopyPointerClasses that can be exploited by ProcXkbSetDeviceInfo() and ProcXkbGetDeviceInfo() to read and write into freed memory. This can lead to local privilege elevation on systems where the X server runs privileged and remote code execution for ssh X forwarding sessions.

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
How this class of weakness works · CWE-416

Memory is used after it has been freed, so its contents — now potentially attacker-controlled — drive the program's behaviour. With careful heap grooming this becomes code execution. The fix requires disciplined ownership of memory and often a targeted rework of the object lifecycle.

General guidance for the use after free class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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
FedoraOperating system
Affected:= 36= 37
Enterprise LinuxOperating system
Affected:= 8.0= 8.1= 9.0
Enterprise Linux AusOperating system
Affected:= 8.4= 8.6
Enterprise Linux DesktopOperating system
Affected:= 7.0
Enterprise Linux EusOperating system
Affected:= 8.4= 8.6= 9.0
Enterprise Linux For Ibm Z SystemsOperating system
Affected:= 7.0= 8.0
Enterprise Linux For Ibm Z Systems EusOperating system
Affected:= 8.4= 8.6
Enterprise Linux For Power Big EndianOperating system
Affected:= 7.0

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

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.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch gitlab.freedesktop.org →
Recommended fix Moderate confidence

Upgrade to the latest version of xorg-x11-server available in your distribution's security repositories (Fedora 38+ or corresponding RHEL/CentOS stream updates containing the fix from commit 0ba6d8c3)

  1. Identify the xorg-x11-server package version currently installed (e.g., `rpm -qa | grep xorg-x11-server` or `dnf list installed xorg-x11-server`)
  2. For Fedora systems: Run `dnf check-update` and then `dnf update xorg-x11-server` to install the latest available security update
  3. For Red Hat Enterprise Linux systems: Run `yum update xorg-x11-server` or `dnf update xorg-x11-server` to apply security errata
  4. Alternatively, for RHEL systems, apply the relevant RHSA (Red Hat Security Advisory) using `yum update --advisory=RHSA-XXXX:YYYY` or `dnf update --advisory=RHSA-XXXX:YYYY`
  5. After updating, restart the X server (or reboot the system) to ensure the vulnerable code is no longer in memory
  6. Verify the updated version is installed: `rpm -qa | grep xorg-x11-server`
Caveat No major breaking changes expected; this is a security fix, but always test updates in a staging environment before deploying to production

Generated from the published advisory — verify against the referenced sources before acting.

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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-2023-0494 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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