Is CVE-2021-34987 actively exploited?

No active exploitation of CVE-2021-34987 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-34987 be exploited remotely?

No. CVE-2021-34987 requires local access to exploit.

What is the CVSS score of CVE-2021-34987?

CVE-2021-34987 has a CVSS score of 8.2 (HIGH).

HOME VULNERABILITIESCVE-2021-34987

HIGH

CVE-2021-34987

CWE-120Published: July 15, 2022· Updated: Jun 17, 2026

8.2

CVSS v3.1

Official Description

This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.5.1 (49187). An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the HDAudio virtual device. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-14969.

NVD Source

Technical Analysis

CVE-2021-34987 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.2.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.