CVE-2023-5090 : What You Need to Know

This is a moderate-severity CVE assigned by Red Hat on September 20, 2023, and published on November 6, 2023. It involves an improper check in

svm_set_x2apic_msr_interception

in the Kernel Virtual Machine (KVM) that may allow direct access to host x2apic msrs.

Understanding CVE-2023-5090

This CVE affects various versions of Red Hat Enterprise Linux and Fedora due to a flaw in KVM that could potentially lead to a denial of service condition.

What is CVE-2023-5090?

The vulnerability arises from an improper check in

svm_set_x2apic_msr_interception()

in KVM, enabling direct access to host x2apic msrs when the guest resets its apic.

The Impact of CVE-2023-5090

This vulnerability could potentially lead to a denial of service condition on the host system, impacting its availability.

Technical Details of CVE-2023-5090

The vulnerability has a base CVSS v3.1 score of 6 (medium severity), with low attack complexity, local attack vector, and high availability impact.

Vulnerability Description

The flaw allows direct access to host x2apic msrs when the guest resets its apic, potentially leading to a denial of service condition.

Affected Systems and Versions

Red Hat Enterprise Linux 6, 7, 8, 9
Fedora

Exploitation Mechanism

The vulnerability may be exploited by a privileged attacker with access to the guest system, leading to potential denial of service.

Mitigation and Prevention

Users and administrators are advised to take immediate steps to mitigate the risks posed by CVE-2023-5090.

Immediate Steps to Take

As of now, no easy mitigation is available that meets Red Hat's security criteria. Users are recommended to apply patches promptly once they become available.

Long-Term Security Practices

Regularly update and patch the affected systems to ensure protection against known vulnerabilities.

Patching and Updates

Keep a close watch on security advisories from Red Hat and apply patches as soon as they are released.

This vulnerability was discovered by Maxim Levitsky (Red Hat) and reported to Red Hat on September 20, 2023, before being made public on September 28, 2023.