Description of the security update for Office Online Server: April 13, 2021 (KB4504714)

Summary

This security update resolves Microsoft Word remote code execution vulnerability, Microsoft Excel remote code execution vulnerability, and Microsoft Excel information disclosure vulnerability. To learn more, see the following security advisories:

• Microsoft Common Vulnerabilities and Exposures CVE-2021-28451
• Microsoft Common Vulnerabilities and Exposures CVE-2021-28453
• Microsoft Common Vulnerabilities and Exposures CVE-2021-28454
• Microsoft Common Vulnerabilities and Exposures CVE-2021-28456

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

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 4504714 for the 64-bit version of Office Online Server

More information

Security update deployment information

For deployment information about this update, see Security update deployment information: April 13, 2021 (KB5001866).

Security update replacement information

This security update replaces previously released security update 4493229.

File hash information

File name	SHA1 hash	SHA256 hash
wacserver2019-kb4504714-fullfile-x64-glb.exe	45ADD0367491A86100BB90D215A186ECE05E1457	EA7F490426AA0ACCA602ABB7E7467F406038F416F595C79837F01419C9BAAD1D

File information

Download the list of files that are included in security update 4504714.

Information about protection and security

Protect yourself online: Windows Security supportLearn how we guard against cyber threats: Microsoft Security