CVE-2021-20203

Publication date 25 February 2021

Last updated 18 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0. It may occur if a guest was to supply invalid values for rx/tx queue size or other NIC parameters. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
qemu	25.10 questing	Fixed 1:6.2+dfsg-2ubuntu5
	25.04 plucky	Fixed 1:6.2+dfsg-2ubuntu5
	24.10 oracular	Fixed 1:6.2+dfsg-2ubuntu5
	24.04 LTS noble	Fixed 1:6.2+dfsg-2ubuntu5
	23.10 mantic	Fixed 1:6.2+dfsg-2ubuntu5
	23.04 lunar	Fixed 1:6.2+dfsg-2ubuntu5
	22.10 kinetic	Fixed 1:6.2+dfsg-2ubuntu5
	22.04 LTS jammy	Fixed 1:6.2+dfsg-2ubuntu5
	21.10 impish	Fixed 1:6.0+dfsg-2expubuntu1.2
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Fixed 1:4.2-3ubuntu6.21
	18.04 LTS bionic	Fixed 1:2.11+dfsg-1ubuntu7.39
	16.04 LTS xenial	Vulnerable
	14.04 LTS trusty	Vulnerable

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=d05dcd94aee88728facafb993c7280547eb4d645

Severity score breakdown

Parameter	Value
Base score	3.2 · Low
Attack vector	Local
Attack complexity	Low
Privileges required	High
User interaction	None
Scope	Changed
Confidentiality	None
Integrity impact	None
Availability impact	Low
Vector	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:L

References

Related Ubuntu Security Notices (USN)

USN-5307-1
QEMU vulnerabilities
28 February 2022