CVE Vulnerabilities

CVE-2021-28692

Improper Privilege Management

Published: Jun 30, 2021 | Modified: Jul 12, 2021
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
CVSS 2.x
5.6 MEDIUM
AV:L/AC:L/Au:N/C:P/I:N/A:C
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

inappropriate x86 IOMMU timeout detection / handling IOMMUs process commands issued to them in parallel with the operation of the CPU(s) issuing such commands. In the current implementation in Xen, asynchronous notification of the completion of such commands is not used. Instead, the issuing CPU spin-waits for the completion of the most recently issued command(s). Some of these waiting loops try to apply a timeout to fail overly-slow commands. The course of action upon a perceived timeout actually being detected is inappropriate: - on Intel hardware guests which did not originally cause the timeout may be marked as crashed, - on AMD hardware higher layer callers would not be notified of the issue, making them continue as if the IOMMU operation succeeded.

Weakness

The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

Affected Software

Name Vendor Start Version End Version
Xen Xen 3.2.0 (including) *
Xen Ubuntu bionic *
Xen Ubuntu groovy *
Xen Ubuntu hirsute *
Xen Ubuntu impish *
Xen Ubuntu kinetic *
Xen Ubuntu lunar *
Xen Ubuntu mantic *
Xen Ubuntu trusty *
Xen Ubuntu xenial *

Potential Mitigations

References