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Security improvements
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).
Before installing this update
Prerequisite:
To apply this update, you must have .NET Framework 4.8 installed.
Install this update
| Release Channel | Available | Next Step |
| Microsoft Update Catalog | Yes | To get the standalone package for this update, go to the Microsoft Update Catalog website. |
| Windows Server Update Services (WSUS) | Yes | This update will automatically sync with WSUS if you configure Products and Classifications as follows: Product:Windows Server 2012 Classification: Security Updates |
To apply this update, you must have .NET Framework 4.8 installed.
You must restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update.
For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:
20200811 Security update deployment information: August 11, 2020
Note We do not recommend that you remove any security update. To remove this update, use the Programs and Features item in Control Panel.
This update does not require a system restart after you apply it unless files that are being updated are locked or are being used.
| File name | SHA1 hash | SHA256 hash |
|---|---|---|
| Windows8-RT-KB4569731-x64-NDP48.msu | 12357630822CEDE469281F3DE4E061E21DA58730 | 570AE47B353D544B27E05D2765818B33F5736433F3C150FB0CCBE33E0E2D3178 |
The MANIFEST files (.manifest) and MUM files (.mum) that are installed are not listed.
| File name | File version | File size | Date | Time | Platform | SP requirement | Service branch |
| Aspnet_perf.dll | 4.8.4210.0 | 41,864 | 30-Jun-2020 | 01:38 | x64 | SPN | AMD64_NETFX4-ASP |
| Aspnet_state_perf.h | Not applicable | 318 | 29-Jun-2020 | 22:16 | Not applicable | SPN | AMD64_NETFX4-ASP |
| Aspnet_state_perf.ini | Not applicable | 42,996 | 30-Jun-2020 | 01:39 | Not applicable | SPN | AMD64_NETFX4-ASP |
| Aspnet_wp.exe | 4.8.4210.0 | 45,448 | 30-Jun-2020 | 01:38 | x64 | SPN | AMD64_NETFX4-ASP |
| System.web.applicationservices.dll | 4.8.4210.0 | 63,752 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
| System.web.extensions.dll | 4.8.4210.0 | 1,842,440 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
| Webengine4.dll | 4.8.4210.0 | 675,200 | 30-Jun-2020 | 01:38 | x64 | None | Not applicable |
| Webengine.dll | 4.8.4210.0 | 21,384 | 30-Jun-2020 | 01:38 | x64 | None | Not applicable |
| System.web.dll | 4.8.4210.0 | 5,396,864 | 30-Jun-2020 | 01:38 | x64 | None | Not applicable |
| System.web.applicationservices.dll | 4.8.4210.0 | 63,752 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
| System.web.extensions.dll | 4.8.4210.0 | 1,842,440 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
| Aspnet_perf.dll | 4.8.4210.0 | 36,224 | 30-Jun-2020 | 01:55 | x86 | SPN | X86_NETFX4-ASP |
| Aspnet_state_perf.h | Not applicable | 318 | 29-Jun-2020 | 22:08 | Not applicable | SPN | X86_NETFX4-ASP |
| Aspnet_state_perf.ini | Not applicable | 42,996 | 30-Jun-2020 | 01:57 | Not applicable | SPN | X86_NETFX4-ASP |
| Aspnet_wp.exe | 4.8.4210.0 | 39,816 | 30-Jun-2020 | 01:55 | x86 | SPN | X86_NETFX4-ASP |
| System.web.extensions.dll | 4.8.4210.0 | 1,842,440 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
| Webengine4.dll | 4.8.4210.0 | 564,616 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
| Webengine.dll | 4.8.4210.0 | 19,320 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
| System.web.dll | 4.8.4210.0 | 5,409,152 | 30-Jun-2020 | 01:55 | x86 | None | Not applicable |
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