This 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.
- All updates for .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, and 4.7.2 require the d3dcompiler_47.dll to be installed. We recommend that you install the included d3dcompiler_47.dll before you apply this update. For more information about the d3dcompiler_47.dll, see KB 4019990.
- 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
For more information about this security update as it relates to Windows Server 2012, see the following article in the Microsoft Knowledge Base:
4345591 Security and Quality Rollup updates for .NET Framework 3.5 SP1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, and 4.7.2 for Windows Server 2012 (KB 4345591)
How to obtain and install the update
Method 1: Windows Update
This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to get security updates automatically, see Windows Update: FAQ.
Method 2: Windows Software Update Services (WSUS)
On your WSUS server, follow these steps:
- Click Start, click Administrative Tools, and then click Microsoft Windows Server Update Services 3.0.
- Expand ComputerName, and then click Action.
- Click Import Updates.
- WSUS opens a browser window in which you may be prompted to install an ActiveX control. You must install the ActiveX control to continue.
- After the ActiveX control is installed, you see the Microsoft Update Catalog screen. Type 4345591 in the Search box, and then click Search.
- Locate the .NET Framework packages that match the operating systems, languages, and processors in your environment. Click Add to add them to your basket.
- After you select all the packages that you require, click View Basket.
- To import the packages to your WSUS server, click Import.
- After the packages are imported, click Close to return to WSUS.
The updates are now available for installation through WSUS.
Update deployment information
For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:
20180814 Security update deployment information: August 14, 2018
Update removal information
Note We do not recommend that you remove any security update. To remove this update, use the Programs and Features item in Control Panel.
Update restart information
This update does not require a system restart after you apply it unless files that are being updated are locked or are being used.
Update replacement information
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