Applies to:
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
Summary
An information disclosure vulnerability exists when the .NET Framework improperly handles objects in memory. An attacker who successfully exploited the vulnerability could disclose contents of an affected system's memory. To exploit the vulnerability, an authenticated attacker would need to run a specially crafted application. The update addresses the vulnerability by correcting how the .NET Framework handles objects in memory.
To learn more about the vulnerabilities, go to the following Common Vulnerabilities and Exposures (CVE).
Important
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As a reminder to advanced IT administrators, updates to .NET Framework 3.5 for Windows 8.1 and Windows Server 2012 R2 should only be applied on systems where .NET Framework 3.5 is present and enabled. Customers who attempt to pre-install updates to .NET Framework 3.5 to offline images that do not contain the .NET Framework 3.5 product enabled will expose these systems to failures to enable .NET Framework 3.5 after the systems are online. For more extensive information about deploying .NET Framework 3.5, see Microsoft .NET Framework 3.5 Deployment Considerations.
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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.
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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 update
The following articles contain additional information about this update as it relates to individual product versions.
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4580469 Description of the Security Only Update for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 for Windows 8.1 and Windows Server 2012 R2 (KB4580469)
How to obtain and install the update
Before installing this update
Prerequisite:
To apply this update, you must have .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 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 8.1 and Windows Server 2012 R2 Classification: Security Updates |
Prerequisites
To apply this update, you must have .NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2 installed.
Restart requirement
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.
Update deployment information
For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:
20201013 Security update deployment information: October 13, 2020
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.
File information The English (United States) version of this software update installs files that have the attributes that are listed in the following tables. Windows 8.1, Windows RT 8.1 and Windows Server 2012 R2 file information
Note: The MANIFEST files (.manifest) and MUM files (.mum) that are installed are not listed.
File information
File hash information
File name |
SHA1 hash |
SHA256 hash |
---|---|---|
Windows8.1-KB4578986-x64.msu |
A8943DA384E133995BE027390813F93A04942AEF |
2814C50D6B28652F0331F54C96AEEE0307E8AB59F12CF18AACC327B7141E7A4F |
Windows8.1-KB4578986-arm.msu |
7B0A343F6A136E34B040E296FEE0E4BDED924084 |
B187213386FC4312DAB1490A27C6BE538D8BF1A296D742A01342B596E1AF5E2E |
Windows8.1-KB4578986-x86.msu |
486FE2BFA5DCFE06D0187551466A9E925B873AEF |
046D7847A57408C64AAC935AFD1D34B5D28EF10D403F19FACEE0F54F621F17AF |
For all supported x64-based versions
File name |
File version |
File size |
Date |
Time |
Platform |
System.security.dll |
4.7.3700.0 |
318,728 |
28-Aug-2020 |
01:31 |
x86 |
System.security.dll |
4.7.3700.0 |
318,728 |
28-Aug-2020 |
01:31 |
x86 |
For all supported ARM-based versions
File name |
File version |
File size |
Date |
Time |
Platform |
System.security.dll |
4.7.3700.0 |
318,728 |
28-Aug-2020 |
01:31 |
x86 |
For all supported x86-based versions
File name |
File version |
File size |
Date |
Time |
Platform |
System.security.dll |
4.7.3700.0 |
318,728 |
28-Aug-2020 |
01:31 |
x86 |
Information about protection and security
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Protect yourself online: Windows Security support
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Learn how we guard against cyber threats: Microsoft Security