January 12, 2021—KB4598231 (OS Build 10240.18818)

Release Date:

Version:

1/12/2021

OS Build 10240.18818

UPDATED 1/12/21
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12/8/20
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 1507 update history home page.

Highlights

  • Updates to improve security when using Microsoft Office products.

  • Updates to improve security when using external devices, such as game controllers, printers, and web cameras.

Improvements and fixes

This security update includes quality improvements. Key changes include:

  • Addresses a security vulnerability issue with HTTPS-based intranet servers. After installing this update, HTTPS-based intranet servers cannot, by default, use a user proxy to detect updates. Scans using these servers will fail if you have not configured a system proxy on the clients. If you must use a user proxy, you must configure the behavior using the policy “Allow user proxy to be used as a fallback if detection using system proxy fails.” To ensure the highest levels of security, also use Windows Server Update Services (WSUS) Transport Layer Security (TLS) certificate pinning on all devices. This change does not affect customers who are using HTTP WSUS servers. For more information, see Changes to scans, improved security for Windows devices.

  • Addresses a security bypass vulnerability that exists in the way the Printer Remote Procedure Call (RPC) binding handles authentication for the remote Winspool interface. For more information, see KB4599464.

  • Security updates to Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Media, Windows Management, Windows Fundamentals, Windows Cryptography, Windows Virtualization, Windows Peripherals, and Windows Hybrid Storage Services.

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

Microsoft is not currently aware of any issues with this update.

How to get this update

Before installing this update

Microsoft strongly recommends that 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 (KB4565911) 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 4598231

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