CVE-2020-29481

Publication date 15 December 2020

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

An issue was discovered in Xen through 4.14.x. Access rights of Xenstore nodes are per domid. Unfortunately, existing granted access rights are not removed when a domain is being destroyed. This means that a new domain created with the same domid will inherit the access rights to Xenstore nodes from the previous domain(s) with the same domid. Because all Xenstore entries of a guest below /local/domain/<domid> are being deleted by Xen tools when a guest is destroyed, only Xenstore entries of other guests still running are affected. For example, a newly created guest domain might be able to read sensitive information that had belonged to a previously existing guest domain. Both Xenstore implementations (C and Ocaml) are vulnerable.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
xen	26.04 LTS resolute	Not affected
	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	Ignored end of life
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Vulnerable
	18.04 LTS bionic	Vulnerable
	16.04 LTS xenial	Vulnerable
	14.04 LTS trusty	Not in release

Notes

mdeslaur

hypervisor packages are in universe. For issues in the hypervisor, add appropriate tags to each section, ex: Tags_xen: universe-binary

Severity score breakdown

CVSS version: CVSS v3.0

Base score 8.8 · High

Base metrics

Parameter	Value
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Changed
Confidentiality impact	High
Integrity impact	High
Availability impact	High

Scores

Parameter	Value
Base score	8.8 · High
Exploitability score	-
Impact score	-

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