CVE-2020-25637

Publication date 6 October 2020

Last updated 18 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A double free memory issue was found to occur in the libvirt API, in versions before 6.8.0, responsible for requesting information about network interfaces of a running QEMU domain. This flaw affects the polkit access control driver. Specifically, clients connecting to the read-write socket with limited ACL permissions could use this flaw to crash the libvirt daemon, resulting in a denial of service, or potentially escalate their privileges on the system. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libvirt	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Not affected
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Fixed 6.0.0-0ubuntu8.16
	18.04 LTS bionic	Fixed 4.0.0-1ubuntu8.21
	16.04 LTS xenial	Vulnerable
	14.04 LTS trusty	Vulnerable

Notes

mdeslaur

Read-only clients can't exploit this flaw. Clients connecting to the read-write socket can exploit this to crash libvirt or possibly execute code, but on Ubuntu, access to the read-write socket already grants root-equivalent permissions, so this flaw has limited impact. Setting priority to negligible.

Patch details

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

Package	Patch details
libvirt	Upstream: 955029b Upstream: 50864dc Upstream: e4116ea Upstream: a63b48c

Severity score breakdown

Parameter	Value
Base score	6.7 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	High
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H