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ParallelsApplication

CVE-2021-34868

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-13712.

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

This is a local privilege escalation vulnerability in Parallels Desktop's Toolgate component. The flaw stems from improper validation of user-supplied data leading to uncontrolled memory allocation, which an attacker with low-privileged code execution on the guest VM can exploit to escalate privileges and execute arbitrary code in the hypervisor context.

MitigationApply the vendor-supplied patch/update for Parallels Desktop. Until patched, restrict VM access to trusted users and minimize the attack surface of guest systems.

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. Identify installed Parallels Desktop version
    Check the Parallels Desktop version information through the application UI (Parallels Desktop menu > About Parallels Desktop) or by running the version check command for your Parallels installation
    Affected if The installed version matches exactly 16.1.3 build 49160
  2. Confirm Toolgate component is active
    Verify that the Toolgate component is loaded and operational in the current Parallels Desktop installation - this is typically a core component used for guest-to-host communication
    Affected if Toolgate is present and enabled in the Parallels Desktop environment
  3. Check for guest VM tool integrations
    Inspect whether Parallels Tools are installed and running within guest virtual machines, as the Toolgate vulnerability is exploited from within the guest VM context
    Affected if Parallels Tools are installed in any guest VM on this host

You are affected if your Parallels Desktop installation is exactly version 16.1.3 build 49160 and the Toolgate component is enabled, as this specific build contains the vulnerability in the Toolgate component that allows guest-to-host privilege escalation.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied patch/update for Parallels Desktop. Until patched, restrict VM access to trusted users and minimize the attack surface of guest systems.

Recommended fix Moderate confidence

Parallels Desktop 17.x or later (current stable release recommended)

  1. 1. Verify the current Parallels Desktop version by navigating to Parallels Desktop > About Parallels Desktop
  2. 2. If version 16.1.3-49160 or any version below 17.0 is installed, download and install the latest version of Parallels Desktop from the official Parallels website (www.parallels.com/products/desktop/download/)
  3. 3. Alternatively, check for updates via Parallels Desktop > Check for Updates
  4. 4. After upgrading, verify the new version number to confirm the update was applied
Caveat Upgrading to major version 17+ may require re-configuration of VM settings and guests; ensure backups of VM images exist before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Parallels Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,760
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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-2021-34868 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
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