CVE-2021-4093

HIGH

KVM - Out-of-bounds reads/writes

Title source: llm
STIX 2.1

Description

A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. This issue results in a crash of the entire system or a potential guest-to-host escape scenario.

References (2)

Core 2
Core References
Issue Tracking, Patch, Third Party Advisory x_refsource_misc
https://bugzilla.redhat.com/show_bug.cgi?id=2028584
Exploit, Mailing List, Patch, Third Party Advisory x_refsource_misc
https://bugs.chromium.org/p/project-zero/issues/detail?id=2222

Scores

CVSS v3 8.8
EPSS 0.0009
EPSS Percentile 25.3%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Details

CWE
CWE-125 CWE-787
Status published
Products (5)
canonical/ubuntu_linux 20.04
canonical/ubuntu_linux 21.10
fedoraproject/fedora 35
linux/linux_kernel 5.11 - 5.14.16
redhat/enterprise_linux 8.0
Published Feb 18, 2022
Tracked Since Feb 18, 2026