CVEvulnerability

CVE-2021-28710

8.8 HIGH Published 2021-11-21 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-11-21
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS 2.0 ([email protected])
6.9 MEDIUM — AV:L/AC:M/Au:N/C:C/I:C/A:C
Weaknesses
CWE-269

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.

Affected configurations

• xen xen 4.15.0 • fedoraproject fedora 35

Related

Weakness · CWE (1)

  • CWE-269 Improper Privilege Management weakness

References