dbcve.org
FedoraOperating system · Fedoraproject

CVE-2023-46839

MEDIUM · 5.3 CVSS v3.1 Published 2024-03-20
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges 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
PCI devices can make use of a functionality called phantom functions, that when enabled allows the device to generate requests using the IDs of functions that are otherwise unpopulated. This allows a device to extend the number of outstanding requests. Such phantom functions need an IOMMU context setup, but failure to setup the context is not fatal when the device is assigned. Not failing device assignment when such failure happens can lead to the primary device being assigned to a guest, while some of the phantom functions are assigned to a different domain.

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

A detailed technical summary for this CVE is being prepared.

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:= 39
XenOperating system
Affected:all versions

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

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

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 xenbits.xenproject.org →
Recommended fix Moderate confidence

Xen stable release containing XSA-449 fix (check xenproject.org for exact version); Fedora system updates

  1. Update the Xen hypervisor to a version that includes the XSA-449 fix. For Fedora systems, apply the latest Fedora security update for the xen package.
  2. After updating Xen, verify the hypervisor version matches the patched release using `xl version` or `xm version`.
  3. Reboot the host into the updated Xen hypervisor to apply the fix.
  4. For guests that had PCI devices assigned, verify the device assignment configuration is intact after the update.
  5. Ensure IOMMU/VT-d is properly enabled in the hypervisor configuration for PCI device isolation.
Caveat Upgrading Xen hypervisor requires host reboot and may require guest configuration review; ensure guest downtime window is scheduled

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

We can apply and verify the patch for your build — typical engagement from $1,600. Get the patch applied

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-46839 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2023-46839 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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