CVE-2021-34854

Hypervisor code execution via uncontrolled Toolgate allocation

Published Oct 25, 2021 · Updated Aug 4, 2024

Privilege escalation in Parallels Desktop 16.1.3 (49160) allows local users to execute arbitrary code in the hypervisor. Toolgate fails to validate guest-supplied data before allocating memory, resulting in an uncontrolled allocation. Exploitation requires low-privileged code execution in a guest system and crosses the guest boundary into hypervisor code execution.

CVSS severity7.8
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Parallels Desktop 16.1.3 (49160) allows local users to execute arbitrary code in the hypervisor. Toolgate fails to validate guest-supplied data before allocating memory, resulting in an uncontrolled allocation. Exploitation requires low-privileged code execution in a guest system and crosses the guest boundary into hypervisor code execution.

The record

CVE
CVE-2021-34854
Published
Oct 25, 2021
Updated
Aug 4, 2024
Vendor
Parallels
Product
Parallels Desktop
Classifications
CWE-770, T1611
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 25, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.1.3 (49160)

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Parallels · Parallels Desktopversion=16.1.3 (49160)

Published CVSS scores

7.8Zero Day InitiativeCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1611Escape to Host

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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