Description of the security update for SharePoint Enterprise Server 2016: July 13, 2021 (KB5001976)

Summary

This security update resolves a Microsoft SharePoint Server spoofing vulnerability, SharePoint Server information disclosure vulnerability, and SharePoint Server remote code execution vulnerability. To learn more about the vulnerabilities, see the following security advisories:

• Microsoft Common Vulnerabilities and Exposures CVE-2021-34517

• Microsoft Common Vulnerabilities and Exposures CVE-2021-34519

• Microsoft Common Vulnerabilities and Exposures CVE-2021-34520

• Microsoft Common Vulnerabilities and Exposures CVE-2021-34467

• Microsoft Common Vulnerabilities and Exposures CVE-2021-34468

This public update delivers Feature Pack 2 for SharePoint Server 2016. Feature Pack 2 contains the following feature:

• SharePoint Framework (SPFx)

This public update also delivers all the features that were included in Feature Pack 1 for SharePoint Server 2016, including:

• Administrative Actions Logging

• MinRole enhancements

• SharePoint Custom Tiles

• Hybrid Taxonomy

• OneDrive API for SharePoint on-premises

• OneDrive for Business modern user experience (available to Software Assurance customers)

The OneDrive for Business modern user experience requires an active Software Assurance contract at the time that the experience is enabled, either by installation of the public update or by manual enablement. If you don't have an active Software Assurance contract at the time of enablement, you must turn off the OneDrive for Business modern user experience.

For more information, see the following Microsoft Docs articles:

• New features included in the November 2016 Public Update for SharePoint Server 2016 (Feature Pack 1)

• New features included in the September 2017 Public Update for SharePoint Server 2016 (Feature Pack 2)

Improvements and fixes

This security update contains fixes for the following nonsecurity issues in SharePoint Server 2016:

• Fixes an issue in which PSConfig doesn't start an administrative instance of Microsoft Edge when you try to use SharePoint Server Central Administration.

• Fixes an issue in which you can't resolve Portal Super User and Portal Super Reader accounts in a multi-tenant farm.

• Fixes an issue in which you can't open the XSL and Parameters editor in Microsoft Edge that's based on Chromium.

• Fixes an issue in which SharePoint Designer doesn't create a forms page under a subsite.

• Fixes an issue in which the Site Aggregator Web Part doesn't add a new tab as expected.

This security update also contains fixes for the following nonsecurity issues in SharePoint Server 2016. To fix the issues completely, you have to install KB 5001981 together with this update.

• Adds the ability to change the ASP.NET view state decryption and validation keys of a SharePoint Server web application. The Set-SPMachineKey PowerShell cmdlet configures and deploys new decryption and validation keys to the servers in the farm. The Update-SPMachineKey PowerShell cmdlet deploys decryption and validation keys to the servers in the farm.

• Fixes an issue that affects the bypass list functionality in the search crawler proxy settings by adding Windows-style wildcard support to the bypass list.

This security update also contains fixes for the following nonsecurity issues in Project Server 2016:

• Fixes an issue in which submitted status updates don't appear for approval after you submit a timesheet.

• In the Scheduled Web Part, the Paste button doesn't paste the cut or copied task to the grid. Paste by using the keyboard (Ctrl+V) does work as expected. However, cut by using the keyboard (Ctrl+X) doesn't work. Ctrl+X copies the task instead of cutting it.

Known issues in this update

Existing workflows might stop functioning in Microsoft SharePoint 2010 workflows after you install this security update for SharePoint Server. Additionally, "c42q8," "c42ra," or "c42rh" event tags are logged in the SharePoint Unified Logging System (ULS) log. For more information, see KB 5004862.

How to get and install the update

More information

Information about protection and security

Protect yourself online: Windows Security support

Learn how we guard against cyber threats: Microsoft Security

Change history

 The following table summarizes some of the most important changes to this topic.