Microsoft .NET Framework 3.5, Microsoft .NET Framework 4.5.2, Microsoft .NET Framework 4.6, Microsoft .NET Framework 4.6.1, Microsoft .NET Framework 4.6.2, Microsoft .NET Framework 4.7, Microsoft .NET Framework 4.7.1, Microsoft .NET Framework 4.7.2
This security update resolves a vulnerability in Microsoft .NET Framework that may cause an information disclosure that allows bypassing Cross-origin Resource Sharing (CORS) configurations.
An attacker who successfully exploits the vulnerability could retrieve from a web application content that's normally restricted.
This security update addresses the vulnerability by enforcing CORS configuration to prevent its bypass.
To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2019-0545.
All updates for Windows 8.1, Windows RT 8.1, and Windows Server 2012 R2 require that update KB 2919355 is installed. We recommend that you install update KB 2919355 on your Windows 8.1-based, Windows RT 8.1-based, or Windows Server 2012 R2-based computer so that you receive updates in the future.
If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.
Additional information about this security update
The following articles contain additional information about this security update as it relates to individual product versions.
4480064 Description of the Security and Quality Rollup for .NET Framework 3.5 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4480064)
4480057 Description of the Security and Quality Rollup for .NET Framework 4.5.2 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4480057)
4480054 Description of the Security and Quality Rollup for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, and 4.7.2 for Windows 8.1, RT 8.1, and Server 2012 R2 (KB 4480054)
How to obtain help and support for this security update