PT-2021-5059 · Xen · Xen

Jan Beulich · Published 2021-11-16 · Updated 2022-10-28 · CVE-2021-28710

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Xen (affected versions not specified)

Description The issue is related to the implementation of Intel Virtualization Technology for Directed I/O (VT-d) in the Xen hypervisor on Intel x86 architecture computers. It involves incorrect handling of the graphics address remapping table. For efficiency reasons, address translation control structures (page tables) may be shared between CPUs for second-level translation (EPT) and IOMMUs. These page tables are set up to be 4 levels deep, but an IOMMU may require only 3 page table levels. When sharing page tables, Xen erroneously skipped stripping the top-level table, allowing the guest to write to leaf page table entries.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Improper Privilege Management

Weakness Enumeration

CWE-269

Related Identifiers

BDU:2021-05834

CVE-2021-28710

Affected Products

Xen

References · 14

• https://nvd.nist.gov/vuln/detail/CVE-2021-28710 · Security Note
• https://osv.dev/vulnerability/CVE-2021-28710 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-05834 · Security Note
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT · Vendor Advisory
• https://xenbits.xenproject.org/xsa/advisory-390.txt · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT · Vendor Advisory
• https://security.gentoo.org/glsa/202208-23 · Vendor Advisory
• https://osv.dev/vulnerability/ALPINE-CVE-2021-28710 · Vendor Advisory
• https://xn--80ahaefyxhn.xn--j1afgaq.xn--p1ai/bin/view/%D0%9E%D0%A1%D0%BD%D0%BE%D0%B2%D0%B0/%D0%9E%D0%B1%D0%BD%D0%BE%D0%B2%D0%BB%D0%B5%D0%BD%D0%B8%D1%8F/2.6 · Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2025046 · Note
• https://security.alpinelinux.org/vuln/CVE-2021-28710 · Note
• https://t.me/cvenotify/24022 · Telegram Post
• https://t.me/cibsecurity/32778 · Telegram Post
• https://t.me/cvenotify/23567 · Telegram Post