CVE-2021-21989

Original summary

Normalized public record · Updated Oct 23, 2026

VMware Workstation (16.x prior to 16.1.2) and Horizon Client for Windows (5.x prior to 5.5.2) contain out-of-bounds read vulnerability in the Cortado ThinPrint component (TTC Parser). A malicious actor with access to a virtual machine or remote desktop may be able to exploit these issues leading to information disclosure from the TPView process running on the system where Workstation or Horizon Client for Windows is installed.

Publisher and source text is retained separately from QFinch interpretation.

Affected products

Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.

Remediation

Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.

1. Confirm the affected product and reachable code path exist in your environment.
2. Apply the vendor-supported patch or mitigation from the primary advisory.
3. Rescan the exact deployed revision and retain verification evidence.

Evidence coverage

SSVC priority

LOW

Confidence

Not available

Aliases

None reported

Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.

Sources and record history

1. Security advisory ↗
2. www.zerodayinitiative.com ↗

Record history

Published May 24, 2021 · Last refreshed Oct 23, 2026