Parallels DesktopApplication · Parallels

CVE-2021-31432

MEDIUM · 6.0 CVSS v3.1 Published 2021-04-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
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 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 IDE virtual device. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. 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-13190.

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 guest-to-host escape vulnerability in Parallels Desktop's IDE virtual device. A local attacker with high-privileged code execution on the guest VM can trigger an out-of-bounds read by supplying malformed data to the IDE controller, potentially disclosing sensitive information from hypervisor memory. The flaw can be chained with other vulnerabilities to achieve arbitrary code execution in the hypervisor context.

MitigationUpdate Parallels Desktop to the vendor-patched version. Until patched, limit trusted access to VMs and avoid running untrusted code in 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
Parallels DesktopApplication
Affected:= 15.1.5-47309

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
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 checks

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

  1. Verify Parallels Desktop is installed
    Check for the presence of Parallels Desktop application in /Applications or via command line: ls /Applications | grep -i parallels
    Affected if Parallels Desktop is found installed on the system
  2. Determine installed Parallels Desktop version
    Run: defaults read /Applications/Parallels\ Desktop.app/Contents/Info.plist CFBundleShortVersionString (or check About Parallels Desktop in the UI)
    Affected if Version returned is exactly 15.1.5 with build number 47309
  3. Check for IDE virtual device configuration in VM
    Open Parallels Desktop, go to Virtual Machine configuration > Hardware > check for IDE controller present in the guest VM settings
    Affected if An IDE controller device is configured and enabled for any guest VM
  4. Identify running guest VMs with IDE devices
    Use prlctl list -a to list all VMs, then prlctl device list <vmname> to check for IDE device attachment
    Affected if Any guest VM is running or configured with an IDE virtual device while Parallels Desktop version is 15.1.5-47309

User is affected if Parallels Desktop version 15.1.5 (build 47309) is installed AND any guest VM uses the IDE virtual device, allowing a high-privileged attacker in the guest to potentially read hypervisor memory.

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

Update Parallels Desktop to the vendor-patched version. Until patched, limit trusted access to VMs and avoid running untrusted code in guest systems.

Fix this in Parallels Desktop Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
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Scan for this in your stack

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dbcve dependency scanner

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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-2021-31432 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