Security Advisory - April 14, 2021

Zscaler protects against 3 new vulnerabilities for Windows

Zscaler, working with Microsoft through their MAPP program, has proactively deployed protection for the following 3 vulnerabilities included in the April 2021 Microsoft security bulletins. Zscaler will continue to monitor exploits associated with all vulnerabilities in the April release and deploy additional protections, as necessary.

CVE-2021-28310 – Win32k Elevation of Privilege Vulnerability

Severity: Important

Affected Software

  • Windows Server, version 20H2 (Server Core Installation)
  • Windows Server, version 2004 (Server Core installation)
  • Windows Server, version 1909 (Server Core installation)
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2019
  • Windows 10 Version 20H2 for x64-based Systems
  • Windows 10 Version 20H2 for ARM64-based Systems
  • Windows 10 Version 20H2 for 32-bit Systems
  • Windows 10 Version 2004 for x64-based Systems
  • Windows 10 Version 2004 for ARM64-based Systems
  • Windows 10 Version 2004 for 32-bit Systems
  • Windows 10 Version 1909 for x64-based Systems
  • Windows 10 Version 1909 for ARM64-based Systems
  • Windows 10 Version 1909 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1803 for x64-based Systems
  • Windows 10 Version 1803 for 32-bit Systems

CVE-2021-28319 – Windows TCP/IP Driver Denial of Service Vulnerability

Severity: Important

Affected Software

  • Windows Server, version 20H2 (Server Core Installation)
  • Windows Server, version 2004 (Server Core installation)
  • Windows Server, version 1909 (Server Core installation)
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2019
  • Windows 10 Version 20H2 for x64-based Systems
  • Windows 10 Version 20H2 for ARM64-based Systems
  • Windows 10 Version 20H2 for 32-bit Systems
  • Windows 10 Version 2004 for x64-based Systems
  • Windows 10 Version 2004 for ARM64-based Systems
  • Windows 10 Version 2004 for 32-bit Systems
  • Windows 10 Version 1909 for x64-based Systems
  • Windows 10 Version 1909 for ARM64-based Systems
  • Windows 10 Version 1909 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1803 for x64-based Systems
  • Windows 10 Version 1803 for 32-bit Systems

CVE-2021-28442 – Windows TCP/IP Information Disclosure Vulnerability

Severity: Important

Affected Software

  • Windows Server, version 20H2 (Server Core Installation)
  • Windows Server, version 2004 (Server Core installation)
  • Windows Server, version 1909 (Server Core installation)
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2019
  • Windows 10 Version 20H2 for x64-based Systems
  • Windows 10 Version 20H2 for ARM64-based Systems
  • Windows 10 Version 20H2 for 32-bit Systems
  • Windows 10 Version 2004 for x64-based Systems
  • Windows 10 Version 2004 for ARM64-based Systems
  • Windows 10 Version 2004 for 32-bit Systems
  • Windows 10 Version 1909 for x64-based Systems
  • Windows 10 Version 1909 for ARM64-based Systems
  • Windows 10 Version 1909 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1803 for x64-based Systems
  • Windows 10 Version 1803 for 32-bit Systems