CVE-2021-28710

 

Published at: - 21-11-2021 04:15

Last modified: - 15-08-2022 01:15

Total changes: - 4

Description

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 table's 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.

Common Vulnerability Scoring System (CVSS)

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

 

Verification logic

 

Reference

• https://xenbits.xenproject.org/xsa/advisory-390.txt
• FEDORA-2021-03645e9807-Mailing List, Third Party Advisory
• GLSA-202208-23-

 

Keywords

NVD

 

CVE-2021-28710

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures