August 11, 2020-KB4570505 Cumulative Update for .NET Framework 3.5, 4.7.2 and 4.8 for Windows 10 Version 1809 and Windows Server 2019

Summary

An elevation of privilege vulnerability exists when ASP.NET or .NET Framework web applications running on IIS improperly allow access to cached files. An attacker who successfully exploited this vulnerability could gain access to restricted files. To exploit this vulnerability, an attacker would need to send a specially crafted request to an affected server. The update addresses the vulnerability by changing how ASP.NET and .NET Framework handle requests.

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

• CVE-2020-1476

A remote code execution vulnerability exists when Microsoft .NET Framework processes input. An attacker who successfully exploited this vulnerability could take control of an affected system. To exploit the vulnerability, an attacker would need to be able to upload a specially crafted file to a web application. The security update addresses the vulnerability by correcting how .NET Framework processes input.

For more information go to: https://go.microsoft.com/fwlink/?linkid=2138023

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

• CVE-2020-1046

For a list of improvements that were released with this update, please see the article links in the Additional Information section of this article.

Additional information about this update

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

• 4569776 Description of the Cumulative Update for .NET Framework 3.5 and 4.7.2 for Windows 10 Version 1809 and Windows Server 2019 (KB4569776)

• 4569750 Description of the Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 1809 and Windows Server 2019 (KB4569750)

Information about protection and security

• Protect yourself online: Windows Security support

• Learn how we guard against cyber threats: Microsoft Security