CVE-2021-4158

Publication date 24 December 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A NULL pointer dereference issue was found in the ACPI code of QEMU. A malicious, privileged user within the guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
qemu	22.04 LTS jammy	Fixed 1:6.2+dfsg-2ubuntu5
	21.10 impish	Fixed 1:6.0+dfsg-2expubuntu1.2
	21.04 hirsute	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Notes

mdeslaur

introduced in 6.0.0

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
qemu	Upstream: https://git.qemu.org/?p=qemu.git;a=commit;h=9bd6565ccee68f72d5012e24646e12a1c662827e

Severity score breakdown

Parameter	Value
Base score	6.0 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	High
User interaction	None
Scope	Changed
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-5307-1
QEMU vulnerabilities
28 February 2022