CVE-2021-34857: (Pwn2Own) Parallels Desktop Toolgate Out-Of-Bounds Write Privilege Escalation Vulnerability

Published Oct 25, 2021
·
Updated

This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3 (49160). 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 Toolgate component. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13601.

Other sources

This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop. 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 Toolgate component. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor.

Affected Software

2 affected components
Parallels Parallels Desktop Macos=16.1.3
Parallels Desktop

Remediation

Event History

Oct 25, 2021
CVE Published
via MITRE·05:10 PM
Data Sourced
via MITRE·05:10 PM
DescriptionSeverityWeakness
Mar 24, 2025
Advisory Published
via ZDI·07:01 PM
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Frequently Asked Questions

1

What is the vulnerability ID for this Parallels Desktop vulnerability?

The vulnerability ID for this Parallels Desktop vulnerability is CVE-2021-34857.

2

What is the severity of CVE-2021-34857?

The severity of CVE-2021-34857 is high with a score of 8.8.

3

How can an attacker exploit CVE-2021-34857?

An attacker can exploit CVE-2021-34857 by executing high-privileged code on the target guest system.

4

Which versions of Parallels Desktop are affected by this vulnerability?

Parallels Desktop 16.1.3 (49160) is affected by CVE-2021-34857.

5

Is there a fix available for CVE-2021-34857?

Yes, a fix is available for CVE-2021-34857. Please refer to the vendor's security advisory for more details.

Contact

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