Note
- Release Date:
February 9, 2021 - Version:
.NET Framework 3.5 and 4.8
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 KB4601554. |
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 2004, Windows Server, version 2004, Windows 10, version 20H2, and Windows Server, version 20H2 Classification: Security Updates |
File information
For a list of the files that are provided in this update, download the file information for cumulative update.
Information about protection and security
- Protect yourself online: Windows Security support
- Learn how we guard against cyber threats: Microsoft Security