What’s Vulnerable › Vulnerabilities

CVE-2021-34857

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-10-25 · updated 2026-06-17
• Weakness: CWE-787

Description

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.

Affected products

• Parallels Desktop: 16.1.3

References

• https://kb.parallels.com/125013
• https://www.zerodayinitiative.com/advisories/ZDI-21-940/
• https://kb.parallels.com/125013
• https://www.zerodayinitiative.com/advisories/ZDI-21-940/

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