CVE-2020-17395
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 escalate privileges on affected installations of Parallels Desktop 15.1.4. 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 prl_naptd process. The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the hypervisor. Was ZDI-CAN-11134.
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 confidenceInteger underflow vulnerability in prl_naptd process of Parallels Desktop 15.1.4 allows local attackers with high-privileged guest code execution to escalate privileges and execute arbitrary code in hypervisor context via improper validation of user-supplied data.
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< 16.0.0CVSS 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
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:H/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 checksWork through these to decide whether this CVE applies to you.
-
Identify Parallels Desktop installation and versionOn macOS, run 'ls /Applications | grep -i parallels' to find the application, then right-click Parallels Desktop.app > Get Info to view version number, or run 'prlctl --version' if Parallels tools are installedAffected if Installed version is below 16.0.0 (any version from 15.1.4 down to earlier versions)
-
Verify prl_naptd component is presentCheck for the existence of the prl_naptd binary by running 'ls /usr/lib/parallels/bin/prl_naptd' or searching with 'find /usr -name prl_naptd 2>/dev/null'Affected if The prl_naptd binary exists on the system (this is the vulnerable component)
-
Confirm prl_naptd process is runningRun 'ps aux | grep prl_naptd' or 'pgrep -a prl_naptd' to check if the process is activeAffected if The prl_naptd process is currently running (indicates the vulnerable service is active)
-
Check guest VM execution environmentReview guest VM configurations via Parallels Desktop UI or 'prlctl list -a' to identify if guest VMs exist and can execute user-supplied codeAffected if Guest virtual machines are configured and can run code (this is the attack prerequisite for privilege escalation)
Environment is affected if Parallels Desktop version is below 16.0.0 and the prl_naptd process is present and running, combined with the presence of guest VMs capable of executing code.
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 data16.0.0
Apply Parallels Desktop security update (version 15.1.5 or later); until patch available, restrict execution of untrusted code on guest virtual machines.
- Consultation2.0 h
- Implementation3.0 h
- Testing4.0 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 $3,040.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-17395 — 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-2020-17395 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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