PT-2021-5818 · Xen+2 · Xen+2

M. Vefa Bicakci + 1 · Published 2021-02-18 · Updated 2022-05-27 · CVE-2021-27379

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Xen versions prior to 4.11.x

Description The issue is related to a lack of privilege management mechanism in the Xen hypervisor on x86 Intel systems. Exploitation of this issue may allow an attacker to access confidential data, compromise its integrity, and cause a denial of service. The problem occurs because a backport missed a flush, resulting in incorrect IOMMU updates, allowing x86 Intel HVM guest OS users to achieve unintended read/write DMA access.

Recommendations For Xen versions prior to 4.11.x, consider applying the necessary patches or updates to ensure correct IOMMU updates and prevent unintended DMA access. As a temporary workaround, restrict access to sensitive data and consider disabling DMA access for guest OS users until a patch is available. 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:2022-00309

CVE-2021-27379

DSA-4888-1

SUSE-SU-2021:1250-1

SUSE-SU-2021:1251-1

SUSE-SU-2021:1252-1

SUSE-SU-2021:1268-1

SUSE-SU-2021_1250-1

SUSE-SU-2021_1268-1

Affected Products

Astra Linux

Suse

Xen

References · 34

• https://bdu.fstec.ru/vul/2022-00309 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-27379 · Vendor Advisory
• https://osv.dev/vulnerability/DSA-4888-1 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se17-bulletin-2021-1126SE17 · Vendor Advisory
• http://xenbits.xen.org/xsa/advisory-366.html · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-27379 · Vendor Advisory
• https://xenbits.xen.org/xsa/advisory-366.html · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se47-bulletin-2022-0114SE47 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2021:1250-1 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-27379 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-27379 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-27379 · Security Note
• https://debian.org/security/2021/dsa-4888 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-27379 · Security Note
• https://osv.dev/vulnerability/CVE-2021-27379 · Vendor Advisory