CVE-2021-4032

Name: CVE-2021-4032
Creator: NVD / NIST
Published: 2022-01-21T19:15:09.827+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.4/10EPSS 0.39%

Last modified Jun 17, 2026

CVE-2021-4032 is a medium-severity vulnerability rated 4.4/10 on the CVSS scale. A vulnerability was found in the Linux kernel's KVM subsystem in arch/x86/kvm/lapic.c kvm_free_lapic when a failure allocation was detected. In this flaw the KVM subsystem may crash the kernel due to mishandling of memory errors that happens during VCPU construction, which allows an attacker with special user privilege to cause a denial of service. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

A vulnerability was found in the Linux kernel's KVM subsystem in arch/x86/kvm/lapic.c kvm_free_lapic when a failure allocation was detected. In this flaw the KVM subsystem may crash the kernel due to mishandling of memory errors that happens during VCPU construction, which allows an attacker with special user privilege to cause a denial of service. This flaw affects kernel versions prior to 5.15 rc7.

Metrics

CVSS 3.1

4.4/10

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

EPSS Probability

0.39%

31.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	<= 5.14
Linux	Linux Kernel	5.15

References

https://bugzilla.redhat.com/show_bug.cgi?id=2027403Issue Tracking, Patch, Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f7d8a19f9a056a05c5c509fa65af472a322abfeeExploit, Patch, Third Party Advisory
https://lkml.org/lkml/2021/9/8/587Exploit, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2027403Issue Tracking, Patch, Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f7d8a19f9a056a05c5c509fa65af472a322abfeeExploit, Patch, Third Party Advisory
https://lkml.org/lkml/2021/9/8/587Exploit, Third Party Advisory

Timeline

Published: Jan 21, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-4032?

How severe is CVE-2021-4032?

CVE-2021-4032 has a CVSS score of 4.4/10 (MEDIUM severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.

How do I fix CVE-2021-4032?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-4032?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST