August 11, 2020—KB4571723 (Security-only update)
Release Date:
11/08/2020
Version:
Security-only update
IMPORTANT Windows 8.1 and Windows Server 2012 R2 have reached the end of mainstream support and are now in extended support. Starting in July 2020, there will no longer be optional, non-security releases (known as "C" releases) for this operating system. Operating systems in extended support have only cumulative monthly security updates (known as the "B" or Update Tuesday release).
IMPORTANT Starting in July 2020, all Windows Updates will disable the RemoteFX vGPU feature because of a security vulnerability. For more information about the vulnerability, seeCVE-2020-1036 and KB4570006. After you install this update, attempts to start virtual machines (VM) that have RemoteFX vGPU enabled will fail, and messages such as the following will appear:
If you re-enable RemoteFX vGPU, a message similar to the following will appear:
-
“The virtual machine cannot be started because all the RemoteFX-capable GPUs are disabled in Hyper-V Manager.”
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“The virtual machine cannot be started because the server has insufficient GPU resources.”
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"We no longer support the RemoteFX 3D video adapter. If you are still using this adapter, you may become vulnerable to security risk. Learn more (https://go.microsoft.com/fwlink/?linkid=2131976)”
Improvements and fixes
This security update includes quality improvements. Key changes include:
-
Security updates to Windows App Platform and Frameworks, Windows Graphics, Windows Media, Windows Shell, Windows Cloud Infrastructure, Windows Authentication, Windows Kernel, Windows Hybrid Cloud Networking, Windows Peripherals, Windows Network Security and Containers, Windows Storage and Filesystems, Windows File Server and Clustering, Windows Hybrid Storage Services, Windows SQL components, Microsoft Scripting Engine, and Windows Remote Desktop.
For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.
Known issues in this update
Symptom |
Workaround |
Certain operations, such as rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, “STATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)”. This occurs when you perform the operation on a CSV owner node from a process that doesn’t have administrator privilege. |
Do one of the following:
Microsoft is working on a resolution and will provide an update in an upcoming release. |
How to get this update
Before installing this update
We strongly recommend that you install the latest servicing stack update (SSU) for your operating system before you install the latest Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Rollup and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.
If you use Windows Update, the latest SSU (KB4566425) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.
REMINDER If you use Security-only updates, you will also need to install all previous Security-only updates and the latest Cumulative Update for Internet Explorer 11.
Install this update
Release Channel |
Available |
Next Step |
Windows Update and Microsoft Update |
No |
See the other options below. |
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, Windows Server 2012 R2, Windows Embedded 8.1 Industry Enterprise, Windows Embedded 8.1 Industry Pro Classification: Security Updates |
File information
For a list of the files that are provided in this update, download the file information for update 4571723.