CVE-2021-34986 Explained : Impact and Mitigation

This article provides an overview of CVE-2021-34986, a vulnerability in Parallels Desktop 16.5.0 (49183) that allows local attackers to escalate privileges and execute arbitrary code.

Understanding CVE-2021-34986

This section delves into the details of the CVE-2021-34986 vulnerability affecting Parallels Desktop.

What is CVE-2021-34986?

CVE-2021-34986 is a vulnerability that enables local attackers to elevate privileges on affected Parallels Desktop installations. Attackers can exploit this flaw within the Parallels Service to execute arbitrary code in the context of root.

The Impact of CVE-2021-34986

The vulnerability poses a high impact level with a CVSS base score of 7.8. It allows attackers to escalate privileges, compromising confidentiality, integrity, and availability of the system.

Technical Details of CVE-2021-34986

This section outlines the technical aspects of CVE-2021-34986 to help understand the vulnerability.

Vulnerability Description

The vulnerability arises from a Time-of-check Time-of-use (TOCTOU) Race Condition within the Parallels Service. Attackers can create symbolic links to manipulate the service and execute files, leading to privilege escalation.

Affected Systems and Versions

Parallels Desktop 16.5.0 (49183) is affected by this vulnerability, exposing systems running this specific version to potential exploitation.

Exploitation Mechanism

To exploit the vulnerability, attackers need the ability to execute low-privileged code on the target system. By creating a symbolic link, attackers can abuse the Parallels Service to execute arbitrary code as root.

Mitigation and Prevention

This section provides guidance on mitigating the risks associated with CVE-2021-34986.

Immediate Steps to Take

Users are advised to update Parallels Desktop to a secure version and avoid executing untrusted code on the system to minimize the risk of exploitation.

Long-Term Security Practices

Implementing least privilege access, regular security updates, and monitoring for suspicious activities can enhance overall system security and resilience.

Patching and Updates

Vendor-released patches addressing the vulnerability should be promptly applied to protect systems from potential exploits.