Linux Kernel up to 6.2.7 on x86-64bit nVMX nested.c nested_vmx_check_guest_state Privilege Escalation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.5	$0-$5k	0.00

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.2.7 on x86-64bit (Operating System). This affects the function nested_vmx_check_guest_state of the file arch/x86/kvm/vmx/nested.c of the component nVMX. The impact remains unknown. The summary by CVE is:

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.

The weakness was presented 04/10/2023 as 112e66017bff7f2837030f34c2bc19501e9212d5. It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2023-30456 since 04/10/2023. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/26/2023).

Upgrading to version 6.2.8 or 6.3-rc3 eliminates this vulnerability. The upgrade is hosted for download at cdn.kernel.org. Applying the patch 112e66017bff7f2837030f34c2bc19501e9212d5 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv3info

VulDB Meta Base Score: 6.6
VulDB Meta Temp Score: 6.5

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

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💳	💳	💳	💳	💳	💳
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege Escalation
CWE: Unknown
ATT&CK: Unknown

Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.2.8/6.3-rc3
Patch: 112e66017bff7f2837030f34c2bc19501e9212d5

Timelineinfo

04/10/2023 Advisory disclosed
04/10/2023 +0 days CVE reserved
04/10/2023 +0 days VulDB entry created
04/26/2023 +16 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: 112e66017bff7f2837030f34c2bc19501e9212d5
Status: Confirmed

CVE: CVE-2023-30456 (🔒)

Entryinfo

Created: 04/10/2023 09:43 AM
Updated: 04/26/2023 12:47 PM
Changes: 04/10/2023 09:43 AM (46), 04/26/2023 12:47 PM (11)
Complete: 🔍