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Horizon ClientApplication · VMware

CVE-2020-3990

MEDIUM · 6.5 CVSS v3.1 Published 2020-09-16
Fix available
A fix is available. Upgrade to 5.4.4 / 16.0.0 or later.
See remediation →
67/100
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
VMware Workstation (15.x) and Horizon Client for Windows (5.x before 5.4.4) contain an information disclosure vulnerability due to an integer overflow issue in Cortado ThinPrint component. A malicious actor with normal access to a virtual machine may be able to exploit this issue to leak memory from TPView process running on the system where Workstation or Horizon Client for Windows is installed. Exploitation is only possible if virtual printing has been enabled. This feature is not enabled by default on Workstation but it is enabled by default on Horizon Client.

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

Integer overflow vulnerability in the Cortado ThinPrint component of VMware Workstation (15.x) and Horizon Client for Windows (before 5.4.4) allows a malicious actor with normal virtual machine access to leak memory from the TPView process. Exploitation requires virtual printing to be enabled, which is not default on Workstation but is enabled by default on Horizon Client.

MitigationDisable virtual printing in VMware Workstation or Horizon Client settings if not required, or update to patched versions (Workstation 15.x or Horizon Client 5.4.4 and later).

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
Horizon ClientApplication
Affected:>= 5.0.0, < 5.4.4
Workstation PlayerApplication
Affected:>= 15.0.0, < 16.0.0
Workstation ProApplication
Affected:>= 15.0.0, < 16.0.0

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
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/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. Identify the installed VMware product and version
    For Workstation: open the application and go to Help > About VMware Workstation to see the exact version number. For Horizon Client: open the client and navigate to Help > About, or check Add/Remove Programs.
    Affected if Version is 15.x for Workstation (any 15.0.0 up to but not including 16.0.0) or between 5.0.0 and 5.4.3 for Horizon Client.
  2. Confirm virtual printing is enabled in Workstation
    Open VMware Workstation, go to Edit > Preferences > Printing (or VM > Settings > Options > Printing). Check if the 'Enable virtual printing' checkbox is checked.
    Affected if Virtual printing is enabled (checkbox is checked). This feature must be active for the vulnerability to be exploitable.
  3. Confirm virtual printing is enabled in Horizon Client
    Open VMware Horizon Client, go to Settings (gear icon) > Client Settings > Printing. Verify if virtual printing is turned on.
    Affected if Virtual printing is enabled. This is enabled by default in Horizon Client and must be disabled for the vulnerability to not apply.
  4. Verify the ThinPrint component is present
    Look for the TPView process or ThinPrint-related files in the VMware installation directory (typically C:\Program Files\VMware\VMware Horizon View\). The presence of ThinPrint components indicates the attack surface exists.
    Affected if ThinPrint/TPView components are installed and running. The vulnerability specifically targets the TPView process.

You are affected if your installed version falls within 15.0.0-15.x for Workstation or 5.0.0-5.4.3 for Horizon Client AND virtual printing is currently enabled.

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
Upgrade available Upgrade to 5.4.4 / 16.0.0 or later
Fixed in 5.4.416.0.0
Interim mitigation

Disable virtual printing in VMware Workstation or Horizon Client settings if not required, or update to patched versions (Workstation 15.x or Horizon Client 5.4.4 and later).

Fix this in Horizon Client Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
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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-2020-3990 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