February 9, 2021—KB4601345 (OS Build 17763.1757) - EXPIRED

^{NEW 8/5/21} EXPIRATION NOTICE

IMPORTANT As of 8/5/2021, this KB is no longer available from Windows Update, the Microsoft Update Catalog, or other release channels. We recommend that you update your devices to the latest security quality update.

^11/17/20 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 1809 update history home page.

Note This release also contains updates for Microsoft HoloLens (OS Build 17763.1757) released February 9, 2021. Microsoft will release an update directly to the Windows Update Client to improve Windows Update reliability on Microsoft HoloLens that have not updated to this most recent OS Build.

Highlights

Updates to improve security when using input devices such as a mouse, keyboard, or pen.
Updates for verifying usernames and passwords.

Improvements and fixes

Addresses a possible elevation of privilege vulnerability in the win32k component.
Updates the Netlogon Elevation of Privilege Vulnerability (CVE-2020-1472) to enable Enforcement mode. For more details, see CVE-2020-1472 and How to manage the changes in Netlogon secure channel connections associated with CVE-2020-1472.
Security updates to Windows App Platform and Frameworks, Windows Apps, Windows Input and Composition, Windows Cloud Infrastructure, Windows Management, Windows Authentication, Windows Fundamentals, Windows Cryptography, Windows Virtualization, and Windows Core Networking.

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 KB4493509, devices with some Asian language packs installed may receive the error, "0x800f0982 - PSFX_E_MATCHING_COMPONENT_NOT_FOUND."

Uninstall and reinstall any recently added language packs. For instructions, see Manage the input and display language settings in Windows 10.
Select Check for Updates and install the April 2019 Cumulative Update. For instructions, see Update Windows 10.

Note If reinstalling the language pack does not mitigate the issue, reset your PC as follows:

Go to the Settings app > Recovery.
Select Get Started under the Reset this PC recovery option.
Select Keep my Files.

Microsoft is working on a resolution and will provide an update in an upcoming release.

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 (KB4601393) 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.
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 4601345.

Note Some files erroneously have “Not applicable” in the “File version” column of the CSV file. This might lead to false positives or false negatives when using some third-party scan detection tools to validate the build.

February 9, 2021—KB4601345 (OS Build 17763.1757) - EXPIRED

Highlights

Improvements and fixes

Known issues in this update

How to get this update

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