Security Only Update for .NET Framework 4.8 for Windows 7 SP1 and Windows Server 2008 R2 SP1 (KB4565589)

Applies to: .NET Framework

Notice


On July 23, 2020, update KB4565589 v2 was released to replace v1 for .NET Framework 4.8 for Windows 7 SP1 and Windows Server 2008 R2 SP1. The v1 update did not install for customers who had certain ESU configurations.  The v2 update corrects the issue for customers who could not install the v1 update.  


If you have already installed KB4565589 v1, no action is necessary.  


To obtain KB4565589 v2, see the “How to obtain and install the update” section.

Summary


A remote code execution vulnerability exists in .NET Framework when the software fails to check the source markup of XML file input. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the process responsible for deserialization of the XML content. To exploit this vulnerability, an attacker could upload a specially crafted document to a server utilizing an affected product to process content. The security update addresses the vulnerability by correcting how .NET Framework validates the source markup of XML content.

This security update affects how .NET Framework's System.Data.DataTable and System.Data.DataSet types read XML-serialized data. Most .NET Framework applications will not experience any behavioral change after the update is installed. For more information on how the update affects .NET Framework, including examples of scenarios which may be affected, please see the DataTable and DataSet security guidance document at https://go.microsoft.com/fwlink/?linkid=2132227.

To learn more about the vulnerabilities, go to the following Common Vulnerabilities and Exposures (CVE).

Additional information about this update


The following articles contain additional information about this update as it relates to individual product versions.
  • 4566466 Description of the Security Only Update for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows 7 SP1 and Windows Server 2008 R2 SP1 (KB4566466)

How to obtain and install the update


Before installing this update

Prerequisite:

To apply this update, you must have .NET Framework 4.8 installed.

You must install the updates listed below and restart your device before installing the latest Rollup. Installing these updates improves the reliability of the update process and mitigates potential issues while installing the Rollup and applying Microsoft security fixes.

  1. The March 12, 2019 servicing stack update (SSU) (KB4490628). To get the standalone package for this SSU, search for it in the Microsoft Update Catalog. This update is required to install updates that are only SHA-2 signed.
  2. The latest SHA-2 update (KB4474419) released September 10, 2019. If you are using Windows Update, the latest SHA-2 update will be offered to you automatically. This update is required to install updates that are only SHA-2 signed. For more information on SHA-2 updates, see 2019 SHA-2 Code Signing Support requirement for Windows and WSUS.
  3. The Extended Security Updates (ESU) Licensing Preparation Package (KB4538483) released February 11, 2020. The ESU licensing preparation package will be offered to you from WSUS. To get the standalone package for ESU licensing preparation package, search for it in the Microsoft Update Catalog.

Install this update

Release Channel Available Next Step
Microsoft Update Catalog Yes To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS) Yes

This update will automatically sync with WSUS if you configure Products and Classifications as follows:

Product: Windows 7 Service Pack 1, Windows Server 2008 R2 Service Pack 1,Windows Embedded Standard 7 Service Pack 1, Windows Embedded POSReady 7

Classification: Security Updates

Restart requirement

You must restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update.

Update deployment information

For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:

20200714 Security update deployment information: July 14, 2020

Update removal information

Note We do not recommend that you remove any security update. To remove this update, use the Programs and Features item in Control Panel.

Update restart information

This update does not require a system restart after you apply it unless files that are being updated are locked or are being used.

File information


The English (United States) version of this software update installs files that have the attributes that are listed in the following tables.

Information about protection and security