CVE-2021-32844 : Exploit Details and Defense Strategies

This article provides detailed information about CVE-2021-32844, a vulnerability found in HyperKit affecting versions 0.20210107 and prior. The issue allows a guest to crash the host, leading to a denial of service.

Understanding CVE-2021-32844

CVE-2021-32844 is a vulnerability in HyperKit, specifically in versions 0.20210107 and earlier. The issue arises from a call to

vc_cfgwrite

that does not check for null in the

vi_pci_write

function, potentially causing the host to crash. This vulnerability can be exploited by a guest to crash the host, resulting in a denial of service.

What is CVE-2021-32844?

CVE-2021-32844 is a NULL pointer dereference vulnerability in HyperKit versions 0.20210107 and prior. It allows an attacker to crash the host system, leading to a denial of service.

The Impact of CVE-2021-32844

The impact of CVE-2021-32844 is the potential for a guest to crash the host system, causing a denial of service. This vulnerability could disrupt the normal operation of the host environment.

Technical Details of CVE-2021-32844

The technical details of CVE-2021-32844 are as follows:

Vulnerability Description

The vulnerability arises from a call to

vc_cfgwrite

that does not check for null in the

vi_pci_write

function, allowing a guest to crash the host.

Affected Systems and Versions

HyperKit versions 0.20210107 and earlier are affected by CVE-2021-32844. Users of these versions are at risk of exploitation.

Exploitation Mechanism

The vulnerability can be exploited by triggering the call to

vc_cfgwrite

without proper null checks, leading to a denial of service.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-32844, users and administrators are advised to take the following steps:

Immediate Steps to Take

Update HyperKit to the fixed commit 451558fe8aaa8b24e02e34106e3bb9fe41d7ad13 to prevent the exploitation of this vulnerability.

Long-Term Security Practices

Regularly update software and components to ensure the latest security patches are applied.
Monitor security advisories for HyperKit and related software for any future vulnerabilities.

Patching and Updates

Make sure to apply patches and updates from the official HyperKit repository to address CVE-2021-32844 and other security issues.