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Release Date:

14/09/2021

Version:

OS Build 14393.4651

7/13/21
IMPORTANT 
This release includes the Flash Removal Package. Taking this update will remove Adobe Flash from the machine. For more information, see the Update on Adobe Flash Player End of Support.    

11/19/20
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. To view other notes and messages, see the Windows 10, version 1607 update history home page

Highlights

  • Updates security for your Windows operating system.  

Improvements and fixes

This security update includes quality improvements. Key changes include:

  • Addresses an issue that prevents users from tracking Distributed Component Object Model (DCOM) activation failures.

  • Addresses an issue that might cause a memory leak to occur during prolonged Remote Desktop audio redirection.

  • Addresses an issue that causes a non-paged memory leak in the FLTMGR.SYS driver. This issue occurs because of a reference count issue in the DFS.SYS driver during cluster failover. As a result, the system might become unresponsive.

  • Addresses an issue with using the robocopy command with the backup option (/B) to fix copy failures. This issue occurs when the source files contain Alternate Data Streams (ADS) or Extended Attributes (EA) and the destination is an Azure Files share.

  • Addresses an issue that causes Authentication Mechanism Assurance (AMA) to stop working. This issue occurs when you migrate to Windows Server 2016 (or newer versions of Windows) and when using AMA in conjunction with certificates from Windows Hello for Business.

  • Addresses an issue that prevents you from writing to a Windows Management Instrumentation (WMI) repository after a low memory condition occurs.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.  

For more information about the resolved security vulnerabilities, please refer to the new Security Update Guide website.

Windows Update Improvements

Microsoft has released an update directly to the Windows Update client to improve reliability. Any device running Windows 10 configured to receive updates automatically from Windows Update, including Enterprise and Pro editions, will be offered the latest Windows 10 feature update based on device compatibility and Windows Update for Business deferral policy. This doesn't apply to long-term servicing editions.

Known issues in this update

Symptom

Workaround

After installing this update, devices which attempt to connect to a network printer for the first time might fail to download and install the necessary printer drivers. Devices which had connected to and installed the printer prior to the installation of KB5005573 are unaffected and operations to that printer will succeed as usual.

This issue has been observed in devices which access printers via a print server using HTTP connections. When a client connects to the server to install the printer, a directory mismatch occurs, which causes the installer files to generate incorrectly. As a result, the drivers may not download.

Note The printer connection methods described in this issue are not commonly used by devices designed for home use. The printing environments affected by this issue are more commonly found in enterprises and organizations.

This issue is resolved in KB5006669.

After installing this update on a print server, printing properties defined on that server might not be correctly provided to clients. Note this issue is specific to print servers and does not impact standard network printing. This issue will not cause printing operations to fail, however, custom settings defined on the server – for example, duplex print settings – will not be applied automatically, and clients will print with default settings only.

This issue results from an improper building of the data file which contains the printer properties. Clients which receive this data file will not be able to use the file content and will instead proceed with default printing settings. Clients who have previously received the settings package prior to the installation of KB5005573 are unaffected. Servers which use default print settings and have no custom settings to provide to clients are unaffected.

Note The printer connection methods described in this issue are not commonly used by devices designed for home use. Printing environments affected by this issue are more commonly found in enterprises and organizations.

This issue is resolved in KB5006669.

After installing this update, you might receive a prompt for administrative credentials every time you attempt to print in environments in which the print server and print client are in different times zones.

Note The affected environments described in this issue are not commonly used by devices designed for home use. The printing environments affected by this issue are more commonly found in enterprises and organizations.

This issue is resolved in KB5006669.

How to get this update

Before installing this update

Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

If you are using Windows Update, the latest SSU (KB5005698) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog

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.

Windows Update for Business

Yes

None. This update will be downloaded and installed automatically from Windows Update in accordance with configured policies.

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

Classification: Security Updates

File information

For a list of the files that are provided in this update, download the file information for cumulative update 5005573.

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