CVE-2021-31423
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 · uneditedThis vulnerability allows local attackers to disclose sensitive information on affected installations of Parallels Desktop 15.1.5-47309. 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 initialization of memory prior to accessing it. An attacker can leverage this in conjunction with other vulnerabilities to escalate privileges and execute arbitrary code in the context of the hypervisor. Was ZDI-CAN-12528.
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 · moderate confidenceThis is a local privilege escalation vulnerability in Parallels Desktop 15.1.5-47309 within the Toolgate component. The flaw stems from improper memory initialization, allowing an attacker with high-privileged code execution on the guest system to disclose sensitive information. When chained with other vulnerabilities, it enables escalation to the hypervisor level for arbitrary code execution.
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= 15.1.5-47309CVSS 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
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Confirm Parallels Desktop is installedLocate the Parallels Desktop application on the system (typically in /Applications on macOS or via system information utilities)Affected if Parallels Desktop software is present on the system
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Identify installed versionCheck the installed version of Parallels Desktop through the application or system utilities (version information is typically available in the application menu under About or in the installation directory)Affected if The installed version matches exactly 15.1.5-47309
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Verify Toolgate component is activeInspect whether the Toolgate feature is enabled or in use within the Parallels Desktop configuration (Toolgate is a paravirtualization interface between guest and host)Affected if Toolgate component is present and active in the current configuration
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Assess guest VM privilege contextReview running virtual machines and their configured privilege levels or user contexts within Parallels DesktopAffected if Guest virtual machines are configured to run with elevated or administrative privileges that could be leveraged in the attack chain
A system is affected only if Parallels Desktop version 15.1.5-47309 is installed with the Toolgate component enabled and guest VMs can execute high-privileged code that could trigger the memory initialization flaw.
Generated from the published advisory. Verify against your own configuration.
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 dataApply the vendor patch for Parallels Desktop when available; prior to patching, restrict execution of untrusted code within virtual machines and minimize the attack surface by limiting guest-to-host interactions.
- Consultation4.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,152.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-31423 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-31423 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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