Description of the security update for Office 2016: December 14, 2021 (KB4504745)

Summary

This security update resolves a Microsoft Office trust center spoofing vulnerability. To learn more about the vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2021-43255.

**Note:**To apply this security update, you must have the release version of Microsoft Office 2016 installed on the computer.

Be aware that the update in the Microsoft Download Center applies to the Microsoft Installer (.msi)-based edition of Office 2016. It doesn’t apply to the Office 2016 Click-to-Run editions, such as Microsoft Office 365 Home. (See What version of Office am I using?)

How to get and install the update

Method 1: Microsoft Update

This update is available from Microsoft Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to get security updates automatically, see Windows Update: FAQ.

Method 2: Microsoft Update Catalog

To get the standalone package for this update, go to the Microsoft Update Catalog website.

Method 3: Microsoft Download Center

You can get the standalone update package through the Microsoft Download Center. Follow the installation instructions on the download page to install the update.

• Download security update 4504745 for the 32-bit version of Office 2016
• Download security update 4504745 for the 64-bit version of Office 2016

More information

Security update deployment information

For deployment information about this update, see Security update deployment information: December 14, 2021 (KB5008541).

Security update replacement information

This security update replaces previously released security update 3178667.

File hash information

File name		SHA256 hash
msodll202016-kb4504745-fullfile-x86-glb.exe		AEAE2E10DE7450AE4F82001681C6FBFE6AB07A4629B294164AA89C148490A20A
msodll202016-kb4504745-fullfile-x64-glb.exe		D21D5D0390DDC4BB2C0A448F3DA1F4800BA739241524194AA9AB76370B755AD3

File information

The English (United States) version of this software update installs files that have the attributes that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.

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For all supported x86-based versions of Office 2016

File identifier	File name	File version	File size	Date	Time
mso20win32client.dll	mso20win32client.dll	16.0.5254.1001	3179384
mso20win32client.dll.x64	mso20win32client.dll	16.0.5254.1001	3179384	6-Dec-21	11:39
mso20win32client.dll.x86	mso20win32client.dll	16.0.5254.1001	1936736	6-Dec-21	11:38

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For all supported x64-based versions of Office 2016

File identifier	File name	File version	File size	Date	Time
mso20win32client.dll	mso20win32client.dll	16.0.5254.1001	3179384
mso20win32client.dll.x64	mso20win32client.dll	16.0.5254.1001	3179384	6-Dec-21	11:39
mso20win32client.dll.x86	mso20win32client.dll	16.0.5254.1001	1936736	6-Dec-21	11:38

Information about protection and security

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