Summary

This security update resolves a remote code execution vulnerability that exists in Microsoft Word software if the program does not correctly handle objects in memory. To learn more about the vulnerability, see the following:

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

Known issues in this update

  • After you install this security update, Office Online Server logging will be set to Verbose by default. We recommend that you change this setting to Medium by running the following command:

    Set-OfficeWebAppsFarm -LogVerbosity “Medium”

    Note After you run the command, you have to restart the Office Online Service. To do this, run the following command:

    Restart-Service WACSM

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.

More information

Security update deployment information

For deployment information about this update, see security update deployment information: March 10, 2020.

Security update replacement information

This security update replaces previously released security update 4484254.

File hash information

File name

SHA1 hash

SHA256 hash

wacserver2019-kb4484270-fullfile-x64-glb.exe

239615C1F3CCBDFF4E943DE3F4879AF28575AE61

EF1396AE918B7AC22FD9E24BD69C5AB8608882C8EA7976BACEDEE17E65E8E5AE

File information

Download the list of files that are included in security update 4484270.

Information about protection and security

Protect yourself online: Windows Security support

Learn how we guard against cyber threats: Microsoft Security

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