Summary

This security update resolves aspoofing vulnerability that exists if Office Online Server does not validate origins in cross-origin communications correctly. To learn more about the vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2020-0695.

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: February 11, 2020.

Security update replacement information

This security update replaces previously released security update 4484223.

File hash information

File name

SHA1 hash

SHA256 hash

wacserver2019-kb4484254-fullfile-x64-glb.exe

A9A416022EB55B6C39CCF6AA890135B815DF72C2

CDD61DFE9D2B46B723C8EA01A9F0DDCA98FCA13980755F200EDBF72C77D3A71B


File information

Download the list of files that are included in security update 4484254.

Information about protection and security

Protect yourself online: Windows Security support

Learn how we guard against cyber threats: Microsoft Security

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