CyberSecBulletin
CVE-2024-31143NVD status: Analyzed

Xen: Unlock of a Resource that is not Locked

CVE-2024-31143 is a high-severity unlock of a resource that is not locked vulnerability in Xen, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 4.16 as the first without the flaw, so updating Xen to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.51% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Xen to 4.16 or a later version.
  2. Read the advisory on xenbits.xenproject.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
XenXen4.4 up to, but not including, 4.164.16

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

An optional feature of PCI MSI called "Multiple Message" allows a device to use multiple consecutive interrupt vectors. Unlike for MSI-X, the setting up of these consecutive vectors needs to happen all in one go. In this handling an error path could be taken in different situations, with or without a particular lock held. This error path wrongly releases the lock even when it is not currently held.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Unlock of a Resource that is not Locked

The product attempts to unlock a resource that is not locked.

More Unlock of a Resource that is not Locked vulnerabilities (CWE-832)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Xen

All Xen vulnerabilities

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