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ParallelsApplication

CVE-2021-34869

HIGH · 8.8 CVSS v3.1 Published 2022-01-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
90/100
Remediation priority · Urgent
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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-13797.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

CVE-2021-34869 is a privilege escalation vulnerability in Parallels Desktop's Toolgate component. The flaw stems from insufficient validation of user-supplied data, leading to uncontrolled memory allocation. An attacker with low-privileged code execution on the guest VM can exploit this to escape the guest and execute arbitrary code with hypervisor-level privileges.

MitigationApply the vendor patch from Parallels that addresses the Toolgate input validation issue. Until patched, restrict VM access to trusted users and minimize the attack surface by disabling unnecessary VM features.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ParallelsApplication
Affected:= 16.1.3-49160

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Parallels Desktop is installed
    Check the /Applications folder for 'Parallels Desktop.app' or run 'ls /Applications | grep -i parallels' in terminal
    Affected if Parallels Desktop application is present on the system
  2. Identify installed Parallels Desktop version
    Run 'defaults read /Applications/Parallels\ Desktop.app/Contents/Info.plist CFBundleVersion' or right-click the app in Finder, select Get Info, and note the Version field
    Affected if Version shows exactly 16.1.3 with build 49160
  3. Locate guest virtual machine configurations
    Check ~/Documents/Parallels/ or /Users/Shared/Parallels/ folders for .pvm virtual machine files, or open Parallels Desktop and view the VM list
    Affected if Any guest VMs are present and accessible
  4. Verify Parallels Tools installation status
    Open Parallels Desktop, select each VM, go to Actions > Install Parallels Tools, or check inside the guest VM for Parallels Tools presence
    Affected if Parallels Tools are installed in any guest VM, enabling the Toolgate component
  5. Assess VM access controls
    Review VM configuration settings for shared folders, clipboard sharing, and network access modes. Check if unprivileged or untrusted users have access to VM console or can execute code within guest VMs
    Affected if Guest VMs allow code execution by untrusted users or have insecure shared feature configurations enabled

You are affected if Parallels Desktop version 16.1.3 build 49160 is installed AND guest VMs with Parallels Tools are accessible to untrusted users who can execute low-privileged code in the guest environment.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch from Parallels that addresses the Toolgate input validation issue. Until patched, restrict VM access to trusted users and minimize the attack surface by disabling unnecessary VM features.

Fix this in Parallels Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,600
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-34869 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data