What’s Vulnerable › Vulnerabilities

CVE-2021-21987

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-05-24 · updated 2026-06-17
• Weakness: CWE-125

Description

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.

Affected products

• VMware Horizon Server: from 5.0.0 before 5.5.2 — fixed in 5.5.2
• VMware Workstation: from 16.0.0 before 16.1.2 — fixed in 16.1.2
• VMware Workstation Pro / Player (Workstation), VMware Horizon Client for Windows: from VMware Workstation (16.x prior through 16.1.2) and Horizon Client for Windows (5.x prior to 5.5.2)

How to fix

Upgrade to a fixed version: VMware Horizon Server 5.5.2; VMware Workstation 16.1.2. Check the vendor advisory for mitigations.

References

• https://www.vmware.com/security/advisories/VMSA-2021-0009.html
• https://www.zerodayinitiative.com/advisories/ZDI-21-608/
• https://www.vmware.com/security/advisories/VMSA-2021-0009.html
• https://www.zerodayinitiative.com/advisories/ZDI-21-608/

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