CVE Vulnerabilities

CVE-2021-28710

Improper Privilege Management

Published: Nov 21, 2021 | Modified: Nov 07, 2023
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS 2.x
6.9 MEDIUM
AV:L/AC:M/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu

certain VT-d IOMMUs may not work in shared page table mode For efficiency reasons, address translation control structures (page tables) may (and, on suitable hardware, by default will) be shared between CPUs, for second-level translation (EPT), and IOMMUs. These page tables are presently set up to always be 4 levels deep. However, an IOMMU may require the use of just 3 page table levels. In such a configuration the lop level table needs to be stripped before inserting the root tables address into the hardware pagetable base register. When sharing page tables, Xen erroneously skipped this stripping. Consequently, the guest is able to write to leaf page table entries.

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 4.15.0 4.15.0

Potential Mitigations

References