CVE-2021-4158 : Security Advisory and Response

A NULL pointer dereference vulnerability in QEMU's ACPI code allows a malicious privileged user in the guest to crash the QEMU process on the host, leading to a denial of service.

Understanding CVE-2021-4158

This section dives into the details of the CVE-2021-4158 vulnerability.

What is CVE-2021-4158?

CVE-2021-4158 is a NULL pointer dereference issue in the ACPI code of QEMU, which could be exploited by a privileged user in the guest to crash the QEMU process on the host.

The Impact of CVE-2021-4158

The exploitation of this vulnerability could result in a denial of service condition, affecting the availability of services running on the host.

Technical Details of CVE-2021-4158

Let's explore the technical aspects of CVE-2021-4158 in this section.

Vulnerability Description

The vulnerability arises from a NULL pointer dereference issue in the ACPI code of QEMU, exposing a potential crash in the host's QEMU process when triggered by a malicious guest user.

Affected Systems and Versions

QEMU versions starting from v6.0.0 and above are affected by CVE-2021-4158.

Exploitation Mechanism

An attacker with guest privileges can exploit the vulnerability by performing specific actions within the guest environment, causing the QEMU process on the host to crash.

Mitigation and Prevention

In this section, we discuss how to mitigate and prevent the exploitation of CVE-2021-4158.

Immediate Steps to Take

System administrators are advised to apply relevant patches and updates provided by the vendor to address the CVE-2021-4158 vulnerability promptly.

Long-Term Security Practices

Implementing robust security practices, such as regular security audits and enforcing the principle of least privilege, can help reduce the risk of similar vulnerabilities.

Patching and Updates

Stay informed about security advisories from QEMU and Red Hat to apply patches and updates as soon as they are available to secure your systems against CVE-2021-4158.