February 9, 2021-KB4601060 Cumulative Update for .NET Framework 3.5 and 4.7.2 for Windows 10, version 1809 and Windows Server, version 2019

Applies To
.NET

Note

  • Release Date:
    February 9, 2021
  • Version:
    .NET Framework 3.5 and 4.7.2

Summary

This security update addresses a denial of service vulnerability in .NET Framework. For more information please see CVE-2021-24111.

Known issues in this update

Symptom After installing this update, WPF apps may crash with a callstack similar to
Exception Info: System.NullReferenceException at System.Windows.Interop.HwndMouseInputProvider.HasCustomChrome(System.Windows.Interop.HwndSource, RECT ByRef) at System.Windows.Interop.HwndMouseInputProvider.GetEffectiveClientRect(IntPtr) at System.Windows.Interop.HwndMouseInputProvider.PossiblyDeactivate(IntPtr, Boolean) at System.Windows.Interop.HwndMouseInputProvider.Dispose()This occurs when disposing an HwndSource whose RootVisual is null, a situation that arises in Visual Studio when docking or splitting windows, and could arise in other apps.
Workaround This issue was resolved in KB4601558.

How to get this update

Install this update

Release Channel Available Next Step
Windows Update and Microsoft Update Yes None. This update will be downloaded and installed automatically from Windows Update.
Microsoft Update Catalog Yes To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS) Yes This update will automatically sync with WSUS if you configure Products and Classifications as follows:
Product: Windows 10, version 1809 and Windows Server, version 2019
Classification: Security Updates

File information

For a list of the files that are provided in this update, download the file information for cumulative update.

Additional information about this update

The following articles contain additional information about this update as it relates to individual product versions.

  • 4601887 Description of the Cumulative Update for .NET Framework 3.5, 4.7.2 and 4.8 for Windows 10, version 1809 and Windows Server, version 2019 (KB4601887)

Information about protection and security