VULNERABILITY INTELLIGENCE

CVE-2021-4093

CVSS score8.8 HIGH

EPSS probability0.42%

CISA KEVNot currently listed

Published2022-02-18

Last modified2026-06-17

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

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.

Weakness classification

CWE-125: Out-of-bounds Read
CWE-787: Out-of-bounds Write

Primary references

secalert@redhat.com — Exploit, Mailing List, Patch, Third Party Advisory
secalert@redhat.com — Issue Tracking, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Exploit, Mailing List, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Patch, Third Party Advisory