Zscaler Security Advisories

Security Advisory - April 11, 2023

Zscaler protects against 5 new vulnerabilities for Windows

  1. Overview
  2. CVE-2023-28274 – Windows Win32k Elevation of Privilege Vulnerability
  3. ​​​​​​​CVE-2023-28285 – Windows Graphics Component Remote Code Execution Vulnerability
  4. ​​​​​​​CVE-2023-24912 – Windows Graphics Component Elevation of Privilege Vulnerability
  5. CVE-2023-28218 – Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
  6. ​​​​​​​CVE-2023-28220 – Layer 2 Tunneling Protocol Remote Code Execution Vulnerability

Zscaler, working with Microsoft through their MAPP program, has proactively deployed protection for the following 5 vulnerabilities included in the April 2023 Microsoft security bulletins. Zscaler will continue to monitor exploits associated with all vulnerabilities in the April release and deploy additional protections, as necessary.

CVE-2023-28274 – Windows Win32k Elevation of Privilege Vulnerability

Severity: Important

Affected Software

  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 11 version 21H2 for ARM64-based Systems
  • Windows 11 version 21H2 for x64-based Systems
  • Windows 10 Version 20H2 for ARM64-based Systems
  • Windows 10 Version 20H2 for 32-bit Systems
  • Windows 10 Version 20H2 for x64-based Systems
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2019
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems

CVE-2023-28285 – Windows Graphics Component Remote Code Execution Vulnerability

Severity: Important

Affected Software

  • Microsoft Office LTSC for Mac 2021
  • Microsoft 365 Apps for Enterprise for 64-bit Systems
  • Microsoft 365 Apps for Enterprise for 32-bit Systems
  • Microsoft Office 2019 for Mac

CVE-2023-24912 – Windows Graphics Component Elevation of Privilege Vulnerability

Severity: Important

Affected Software

  • Windows Server 2012 R2 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2016 (Server Core installation)
  • Windows Server 2016
  • Windows 10 Version 1607 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 for x64-based Systems
  • Windows 10 for 32-bit Systems
  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 11 version 21H2 for ARM64-based Systems
  • Windows 11 version 21H2 for x64-based Systems
  • Windows 10 Version 20H2 for ARM64-based Systems
  • Windows 10 Version 20H2 for 32-bit Systems
  • Windows 10 Version 20H2 for x64-based Systems
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2019
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems

CVE-2023-28218 – Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

Severity: Important

Affected Software

  • Windows Server 2012 R2 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2016 (Server Core installation)
  • Windows Server 2016
  • Windows 10 Version 1607 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 for x64-based Systems
  • Windows 10 for 32-bit Systems
  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 11 version 21H2 for ARM64-based Systems
  • Windows 11 version 21H2 for x64-based Systems
  • Windows 10 Version 20H2 for ARM64-based Systems
  • Windows 10 Version 20H2 for 32-bit Systems
  • Windows 10 Version 20H2 for x64-based Systems
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2019
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems

CVE-2023-28220 – Layer 2 Tunneling Protocol Remote Code Execution Vulnerability

Severity: Critical

Affected Software

  • Windows Server 2012 R2 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2016 (Server Core installation)
  • Windows Server 2016
  • Windows 10 Version 1607 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 for x64-based Systems
  • Windows 10 for 32-bit Systems
  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for x64-based Systems
  • Windows 11 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 11 version 21H2 for ARM64-based Systems
  • Windows 11 version 21H2 for x64-based Systems
  • Windows 10 Version 20H2 for ARM64-based Systems
  • Windows 10 Version 20H2 for 32-bit Systems
  • Windows 10 Version 20H2 for x64-based Systems
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2019
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems