CVE-2021-21989: 
VMware Workstation Player vulnerability analysis and mitigation

VMware Workstation (16.x prior to 16.1.2) and Horizon Client for Windows (5.x prior to 5.5.2) contain an out-of-bounds read vulnerability in the Cortado ThinPrint component, specifically in the TTC Parser (CVE-2021-21989). The vulnerability was discovered and reported by an anonymous researcher working with Trend Micro's Zero Day Initiative, and VMware released patches in May 2021 (VMware Advisory, ZDI Advisory).

The vulnerability exists within the ThinPrint component, specifically affecting the TTC Parser. The issue can result in an out-of-bounds read vulnerability when processing crafted data in a font file. VMware has evaluated this vulnerability with a CVSS v3.1 base score of 6.5 MEDIUM (Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N). The exploitation is only possible if virtual printing has been enabled, which is not enabled by default on Workstation but is enabled by default on Horizon Client for Windows (VMware Advisory).

A successful exploitation of this vulnerability could allow an attacker to disclose sensitive information from the TPView process running on the system where Workstation or Horizon Client for Windows is installed (ZDI Advisory, VMware Advisory).

VMware has released patches to address this vulnerability. Users should upgrade VMware Workstation to version 16.1.2 and Horizon Client for Windows to version 5.5.2. No workarounds are available for this vulnerability (VMware Advisory).