Security Only updates for .NET Framework 3.5, 4.5.2, 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 4345681)

Summary

This security update resolves an information disclosure vulnerability in Microsoft .NET Framework that could allow an attacker to access information in multi-tenant environments. The vulnerability is caused when .NET Framework is used in high-load/high-density network connections in which content from one stream can blend into another stream.

To exploit the vulnerability, an attacker who can access one tenant in a high-load/high-density environment could potentially trigger multi-tenanted data exposure from one customer to another.

This security update addresses the vulnerability by correcting the way that .NET Framework handles high-load/high-density network connections.

To learn more about this vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2018-8360.

Important

• All updates for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 require update 2919355 to be installed. We recommend that you install update 2919355 on your Windows RT 8.1-based, Windows 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.

• 4344178 Description of the Security Only update for .NET Framework 3.5 for Windows 8.1, RT 8.1 and Server 2012 R2 (KB 4344178)

• 4344171 Description of the Security Only update for .NET Framework 4.5.2 for Windows 8.1, RT 8.1 and Server 2012 R2 (KB 4344171)

• 4344166 Description of the Security Only update 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 4344166)

How to obtain help and support for this security update

• Help for installing updates: Windows Update FAQ

• Security solutions for IT professionals: TechNet Security Support and Troubleshooting

• Help for protecting your Windows-based products and services from viruses and malware: Microsoft Secure

• Local support according to your country: International Support