dbcve.org
FedoraOperating system · Fedoraproject

CVE-2023-46842

MEDIUM · 6.5 CVSS v3.1 Published 2024-05-16
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
67/100
Remediation priority · Elevated
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
Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and other modes. This in particular means that they may set registers used to pass 32-bit-mode hypercall arguments to values outside of the range 32-bit code would be able to set them to. When processing of hypercalls takes a considerable amount of time, the hypervisor may choose to invoke a hypercall continuation. Doing so involves putting (perhaps updated) hypercall arguments in respective registers. For guests not running in 64-bit mode this further involves a certain amount of translation of the values. Unfortunately internal sanity checking of these translated values assumes high halves of registers to always be clear when invoking a hypercall. When this is found not to be the case, it triggers a consistency check in the hypervisor and causes a crash.

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-843

A resource is accessed as one type when it was actually allocated as another, so the code misreads memory layout — in interpreters and language runtimes this is frequently a direct path to code execution. It often arises from unchecked casts on attacker-influenced objects. The fix is strict type checks before casts and memory-safe access patterns.

General guidance for the type confusion 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:= 38= 40
XenOperating system
Affected:>= 3.2.0

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
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/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 xenbits.xenproject.org →
Recommended fix Moderate confidence

Xen 4.18.0 or later; or latest Fedora Xen package updates

  1. Identify the current Xen version installed on the system using: rpm -q xen or dnf list installed xen
  2. For Fedora systems, update Xen packages to the latest available version: dnf update xen
  3. Alternatively, if running Xen directly (not via Fedora packages), upgrade Xen to version 4.18.0 or later which contains the fix for XSA-454
  4. Reboot the system to load the updated hypervisor
  5. Verify the Xen version after reboot: xl info | grep xen_version
Caveat Standard Xen upgrade considerations apply - ensure guest VM compatibility and backup critical VM state before rebooting the host

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-2023-46842 — 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-2023-46842 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