October 13, 2020—KB4580347 (Monthly Rollup)

Applies to: Windows 8.1Windows Server 2012 R2Windows Embedded 8.1 Industry Enterprise

Improvements and fixes


This security update includes improvements and fixes that were a part of update KB4577066 (released September 8, 2020) and addresses the following issues:

  • Corrects the end date for daylight savings time (DST) in 2021 for the Fiji Islands. For more information, see DST correction in Windows for the Fiji Islands: October 13, 2020.
  • Addresses an issue where Group Policy recursively deletes critical files when the "Delete local user profile policy" is enabled.
  • Addresses an issue in which a Null port is created through the user interface.
  • Adds a notification to Internet Explorer 11 that informs users about the end of support for Adobe Flash in December 2020. For more information, see KB4581051.
  • Addresses an issue with Microsoft Edge IE Mode that occurs when you enable Configure enhanced hang detection for Internet Explorer mode in Microsoft Edge. 
  • Allows administrators to disable JScript in specific security zones.
  • Security updates to Windows App Platform and Frameworks, Windows Graphics, Windows Shell, Windows Silicon Platform, Windows Cloud Infrastructure, Windows Fundamentals, Windows Authentication, Windows Virtualization, Windows Kernel, Windows Core Networking, Windows Network Security and Containers, Windows Remote Desktop, and Windows SQL components.

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:

  • Perform the operation from a process that has administrator privilege.
  • Perform the operation from a node that doesn’t have CSV ownership.

Microsoft is working on a resolution and will provide an update in an upcoming release.

When installing a third-party driver, you might receive the error, “Windows can’t verify the publisher of this driver software”. You may also see the error “No signature was present in the subject” when attempting to view the signature properties using Windows Explorer.

This issue occurs when one or more of the following is present in a driver package:

  • An improperly formatted catalog file is identified during validation by Windows. Starting with this release, Windows will require the validity of DER encoded PKCS#7 content in catalog files. Catalogs files must be signed per section 11.6 of describing DER-encoding for SET OF members in X.690.
  • A driver catalog file extension is not one of supported extensions.

If this happens you should contact the driver vendor or device manufacturer (OEM) and ask them for an updated driver to correct the issue.

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

Install this update

Release Channel Available Next Step
Windows Update and Microsoft Update Yes None. This update will be downloaded and installed automatically from Windows Update.
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 4580347