July 14, 2020-KB4565633 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 1903 and Windows Server 1903 RTM and Windows 10, version 1909 and Windows Server, version 1909

Applies to: .NET Framework

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).

Known issues in this update


Microsoft is not currently aware of any issues in this update.

How to get this update


Install this update

Release Channel Available Next Step
Windows Update and Microsoft Update Yes None. This update will be downloaded and installed automatically from Windows Update.
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 10 Version 1903 and Windows Server 1903 RTM and Windows 10, version 1909 and Windows Server, version 1909

Classification: Security Updates

File information

For a list of the files that are provided in this update, download the file information for cumulative update .

Information about protection and security