Is CVE-2021-34855 actively exploited?

No active exploitation of CVE-2021-34855 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-34855 be exploited remotely?

No. CVE-2021-34855 requires local access to exploit.

What is the CVSS score of CVE-2021-34855?

CVE-2021-34855 has a CVSS score of 6.5 (MEDIUM).

HOME VULNERABILITIESCVE-2021-34855

MEDIUM

CVE-2021-34855

CWE-908Published: October 25, 2021· Updated: Jun 17, 2026

6.5

CVSS v3.1

Official Description

This vulnerability allows local attackers to disclose sensitive information on affected installations of Parallels Desktop 16.1.3 (49160). An attacker must first obtain the ability to execute low-privileged code on the target guest system in order to exploit this vulnerability. The specific flaw exists within the Toolgate component. The issue results from the lack of proper initialization of memory prior to accessing it. An attacker can leverage this in conjunction with other vulnerabilities to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13592.

NVD Source

Technical Analysis

CVE-2021-34855 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low 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), with a CVSS base score of 6.5.

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.