Description of the security update for SharePoint Server Subscription Edition: March 12, 2024 (KB5002564)

Summary

This security update resolves a Microsoft SharePoint Server remote code execution vulnerability. To learn more about the vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2024-21426.

Improvements and fixes

This security update introduces the SharePoint Server Subscription Edition Version 24H1 feature update. This feature update will be included in all SharePoint Server Subscription Edition public updates going forward. For more information about this feature update, see New and improved features in SharePoint Server Subscription Edition Version 24H1.

This security update contains improvements and fixes for the following nonsecurity issues in SharePoint Server Subscription Edition:

• Allows users to disable SharePoint's Content Security Policy (CSP) HTTP header in SharePoint Pages. If you don't want to enable the SharePoint CSP HTTP header in SharePoint Pages, you can run the following cmdlets in PowerShell:
  
  Add-PSSnapin Microsoft.SharePoint.PowerShell
  $farm = Get-SPFarm
  $farm.EnableCSPHeaderForPage = $false
  $farm.Update()

• Fixes an issue in which the modern List web part freezes when you select the See all link for a grouped view if the site URL contains the apostrophe (') character.

• Fixes an issue in which the Edit button overlaps the multiline field title in the list item editing pane when you use right-to-left (RTL) languages.

• Fixes an issue in which horizontal navigation of the communication site doesn't reflect the current site correctly.

• Fixes an issue in which SharePoint site theme customization delays the login form by 5 seconds while the form tries to load.

• Fixes an issue in which plain text will be rendered as a hyperlink in quick edit mode.

• Fixes an issue in which the classic UI doesn't show the correct status of a subsite.

Known issues in this update

• After you install this security update, you may encounter an issue in which servers cannot join an existing SharePoint farm. For more information, see Can't add a server to a SharePoint farm if the farm contains a certificate managed by Certificate Management (KB5037978).

• This security update also introduces a newer version of the Microsoft.Owin component. Because this component's version is referenced in SharePoint Server's Web.config files, you must run an upgrade action to update the reference in these Web.config files. If you install this security update without running the upgrade action, you will receive the following error message when you browse to SharePoint sites:

  Could not load file or assembly 'Microsoft.Owin, Version=3.0.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

  After you install this security update, run the upgrade action by using one of the following methods:

  • Start the SharePoint Products and Technologies Configuration Wizard (PSConfigUI.exe) and upgrade.

  • Run the SharePoint Products Configuration Wizard (PSCONFIG.EXE) command line tool:
    
    PSCONFIG.EXE -cmd secureresources -cmd services -install -cmd installfeatures -cmd applicationcontent -install -cmd upgrade -inplace b2b -wait

  • Run the following PowerShell commands:
    
    Initialize-SPResourceSecurity
    Install-SPService
    Install-SPFeature -AllExistingFeatures
    Install-SPApplicationContent
    Upgrade-SPFarm

  After you run this upgrade action, the error message disappears.

  This behavior is by design because the new component version must be registered in SharePoint Server's Web.config files.

  This issue will affect the ability of users to do "zero downtime patching" (ZDP), as described in SharePoint Server zero downtime patching steps. This is because SharePoint sites won't be accessible until the upgrade action is run. Users should be prepared to install the update during a maintenance window when downtime is acceptable.

  Alternatively, users can avoid downtime by manually editing the Web.config file for each of their web applications immediately after the update is installed on a given server and before the server is returned to the load balancing rotation. To do this, follow these steps:

  1. Locate the following lines in the configuration > runtime > assemblyBinding section of the Web.config file:

     <dependentAssembly>
          <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" culture="neutral" />
          <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
     </dependentAssembly>

  2. Replace the located text with the following lines:

     <dependentAssembly>
          <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" culture="neutral" />
          <bindingRedirect oldVersion="0.0.0.0-4.2.2.0" newVersion="4.2.2.0" />
     </dependentAssembly>

  After the update is installed on all servers, users can run the upgrade action. Manually editing the Web.config file won't interfere with the upgrade action.

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.