How severe is CVE-2021-34854?

CVE-2021-34854 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-34854 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34854?

CVE-2021-34854 affects Parallels Parallels Desktop. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-34854?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-34854 published?

CVE-2021-34854 was published on 2021-10-25 and last updated on 2026-06-17.

CVE-2021-34854

CVE-2021-34854 is a high-severity vulnerability in Parallels Parallels Desktop with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Parallels Parallels Desktop
Published: 2021-10-25
Last modified: 2026-06-17

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 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 validation of user-supplied data, which can result in an uncontrolled memory allocation. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13544.

Frequently asked questions

What is CVE-2021-34854?: 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 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 validation of user-supplied data, which can result in an uncontrolled memory allocation. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-13544.
How severe is CVE-2021-34854?: CVE-2021-34854 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-34854 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34854?: CVE-2021-34854 affects Parallels Parallels Desktop. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-34854?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-34854 published?: CVE-2021-34854 was published on 2021-10-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:parallels:parallels_desktop:16.1.3:*:*:*:*:macos:*:*

More vulnerabilities in Parallels Parallels Desktop

CVE-2025-31359 — High (CVSS 8.8): A directory traversal vulnerability exists in the PVMP package unpacking functionality of Parallels Desktop for Mac…
CVE-2022-34890 — High (CVSS 8.8): This vulnerability allows local attackers to disclose sensitive information on affected installations of Parallels…
CVE-2021-34864 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3…
CVE-2021-34857 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3…
CVE-2021-34856 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.1.3…
CVE-2021-31426 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop…

All CVEs affecting Parallels Parallels Desktop →

Other CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities

CVE-2026-31283 — Critical (CVSS 9.8): In Totara LMS v19.1.5 and before, the forgot password API does not implement rate limiting for the target email…
CVE-2020-37067 — Critical (CVSS 9.8): Filetto 1.0 FTP server contains a denial of service vulnerability in the FEAT command processing that allows attackers…
CVE-2021-47875 — Critical (CVSS 9.8): GeoGebra CAS Calculator 6.0.631.0 contains a denial of service vulnerability that allows attackers to crash the…
CVE-2025-11832 — Critical (CVSS 9.8): Allocation of Resources Without Limits or Throttling vulnerability in Azure Access Technology BLU-IC2, Azure Access…
CVE-2024-44241 — Critical (CVSS 9.8): The issue was addressed with improved bounds checks. This issue is fixed in iOS 18.1 and iPadOS 18.1, macOS Sequoia…
CVE-2022-3439 — Critical (CVSS 9.8): Allocation of Resources Without Limits or Throttling in GitHub repository ikus060/rdiffweb prior to 2.5.0.

Browse all CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities →