// For flags

CVE-2023-30456

kernel: KVM: nVMX: missing consistency checks for CR0 and CR4

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

An issue was discovered in arch/x86/kvm/vmx/nested.c in the Linux kernel before 6.2.8. nVMX on x86_64 lacks consistency checks for CR0 and CR4.

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.

It was discovered that the Broadcom FullMAC USB WiFi driver in the Linux kernel did not properly perform data buffer size validation in some situations. A physically proximate attacker could use this to craft a malicious USB device that when inserted, could cause a denial of service (system crash) or possibly expose sensitive information. Reima Ishii discovered that the nested KVM implementation for Intel x86 processors in the Linux kernel did not properly validate control registers in certain situations. An attacker in a guest VM could use this to cause a denial of service (guest crash). Various other issues were also addressed.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2023-04-10 CVE Reserved
  • 2023-04-10 CVE Published
  • 2025-03-19 CVE Updated
  • 2025-04-27 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-358: Improperly Implemented Security Check for Standard
  • CWE-754: Improper Check for Unusual or Exceptional Conditions
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.2.8
Search vendor "Linux" for product "Linux Kernel" and version " < 6.2.8"
-
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
6.3
Search vendor "Linux" for product "Linux Kernel" and version "6.3"
rc1
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
6.3
Search vendor "Linux" for product "Linux Kernel" and version "6.3"
rc2
Affected