CVE-2023-30456

Description

A flaw was found in the KVM's Intel nested virtualization feature (nVMX). The effective values of the guest CR0 and CR4 registers could differ from those included in the VMCS12. In rare circumstances (i.e., kvm_intel module loaded with parameters nested=1 and ept=0) this could allow a malicious guest to crash the host system, causing a denial of service.

Statement

Red Hat currently provides the nested virtualization feature as a Technology Preview. Nested virtualization is therefore unsupported for production use. For more information please refer to https://access.redhat.com/solutions/21101 and https://access.redhat.com/support/offerings/techpreview.

Mitigation

This vulnerability can be mitigated by disabling the nested virtualization feature:

# modprobe -r kvm_intel
# modprobe kvm_intel nested=0

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score66.56.5
Attack VectorLocalLocalLocal
Attack ComplexityLowLowLow
Privileges RequiredHighLowLow
User InteractionNoneNoneNone
ScopeChangedChangedChanged
ConfidentialityNoneNoneNone
Integrity ImpactNoneNoneNone
Availability ImpactHighHighHigh

Vector

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

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

cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Understanding the Weakness (CWE)

CWE-358

Access Control

Technical Impact: Bypass Protection Mechanism

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