July 14, 2020-KB4566516 Cumulative Update for .NET Framework 3.5, 4.7.2 and 4.8 for Windows 10 Version 1809 and Windows Server 2019

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).

• CVE-2020-1147

Additional information about this update

The following articles contain additional information about this update as it relates to individual product versions.

• 4565625 Description of the Cumulative Update for .NET Framework 3.5 and 4.7.2 for Windows 10 Version 1809 and Windows Server 2019 (KB4565625)

• 4565632 Description of the Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 1809 and Windows Server 2019 (KB4565632)

Information about protection and security

• Protect yourself online: Windows Security support

• Learn how we guard against cyber threats: Microsoft Security