August 13, 2024—KB5041578 (OS Build 17763.6189)

11/17/20
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. For an overview of Windows 10, version 1809, see its update history page.

**Important:**Windows updates do not install Microsoft Store application updates. If you are an enterprise user, see Microsoft Store apps - Configuration Manager. If you are a consumer user, see Get updates for apps and games in Microsoft Store.

Highlights

• This update addresses security issues for your Windows operating system.

Improvements

This security update includes improvements. Below is a summary of the key issues that this update addresses when you install this KB. If there are new features, it lists them as well. The bold text within the brackets indicates the item or area of the change we are documenting.

• [Protected Process Light (PPL) protections] You can bypass them.
• [Windows Kernel Vulnerable Driver Blocklist file (DriverSiPolicy.p7b)] This update adds to the list of drivers that are at risk for Bring Your Own Vulnerable Driver (BYOVD) attacks.
• [BitLocker (known issue)] A BitLocker recovery screen shows when you start up your device. This occurs after you install the July 9, 2024, update. This issue is more likely to occur if device encryption is on. Go toSettings>Privacy & Security>Device encryption. To unlock your drive, Windows might ask you to enter the recovery key from your Microsoft account.
• [Lock screen] This update addresses CVE-2024-38143. Because of this, the “Use my Windows user account” checkbox is not available on the lock screen to connect to Wi-Fi.
• [NetJoinLegacyAccountReuse] This update removes this registry key. For more information refer to KB5020276—Netjoin: Domain join hardening changes.
• **[Secure Boot Advanced Targeting (SBAT) and Linux Extensible Firmware Interface (EFI)]**This update applies SBAT to systems that run Windows. This stops vulnerable Linux EFI (Shim bootloaders) from running. This SBAT update will not apply to systems that dual-boot Windows and Linux. After the SBAT update is applied, older Linux ISO images might not boot. If this occurs, work with your Linux vendor to get an updated ISO image.
• [Domain Name System (DNS)] This update hardens DNS server security to address CVE-2024-37968. If the configurations of your domains are not up to date, you might get the SERVFAIL error or time out.
• **[Line Printer Daemon (LPD) protocol]**Using this deprecated protocol to print might not work as you expect or fail. This issue occurs after you install the July 9, 2024, and later updates.NoteWhen it is no longer available, clients, like UNIX, that use it will not connect to a server to print. UNIX clients should use the Internet Printing Protocol (IPP). Windows clients can connect to shared UNIX printers using the Windows Standard Port Monitor.
  If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.For more information about security vulnerabilities, please refer to the new Security Update Guide website and the August 2024 Security Updates.

Windows 10 servicing stack update (KB5041577) - 17763.6174

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

Known issues in this update

Symptom	Workaround
After installing the Windows update released on or after July 9, 2024, Windows Servers might affect Remote Desktop Connectivity across an organization. This issue might occur if legacy protocol (Remote Procedure Call over HTTP) is used in Remote Desktop Gateway. Resulting from this, remote desktop connections might be interrupted.This issue might occur intermittently, such as repeating every 30 minutes. At this interval, logon sessions are lost and users will need to reconnect to the server. IT administrators can track this as a termination of the TSGateway service which becomes unresponsive with exception code 0xc0000005.	​​​​​​​This issue is addressed in KB5043050.
After installing this security update, you might observe that some Windows Server 2019 devices experience system slowdowns, unresponsiveness, and high CPU usage particularly with Cryptographic Services. A limited number of organizations reported that the issue was observed when the device was running an Antivirus software which performs scans against the ‘%systemroot%\system32\catroot2’ folder for Windows updates, due to an error with catalog enumeration. Our investigations so far indicate that this issue is limited to some specific scenarios. If your IT environment is affected, you might observe that your devices:

• Show increased CPU utilization
• Experience increased disk latency/ disk utilization
• Indicate degraded OS or application performance
• Show that the CryptSVC service fails to start
• May boot into a black screen
• Experience slow to boot
• Freeze or hang
  | This issue is addressed in KB5043050.
  After installing this security update, you might face issues with booting Linux if you have enabled the dual-boot setup for Windows and Linux in your device. Resulting from this issue, your device might fail to boot Linux and show the error message “Verifying shim SBAT data failed: Security Policy Violation. Something has gone seriously wrong: SBAT self-check failed: Security Policy Violation.”The August 2024 Windows security update applies a Secure Boot Advanced Targeting (SBAT) setting to devices that run Windows to block old, vulnerable boot managers. This SBAT update will not be applied to devices where dual booting is detected. On some devices, the dual-boot detection did not detect some customized methods of dual-booting and applied the SBAT value when it should not have been applied.| Please refer to the workaround mentioned in Windows release health site for this issue.

How to get this update

Before you install this updateMicrosoft now combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions. Prerequisite:You**must **install the August 10, 2021 SSU (KB5005112) before installing the LCU.Install this updateTo install this update, use one of the following Windows and Microsoft release channels.

Windows UpdateBusinessCatalogServer Update Services

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

Available	Next Step
Yes	None. This update will be downloaded and installed automatically from Windows Update for Business in accordance with configured policies.

Available	Next Step
Yes	To get the standalone package for this update, go to the Microsoft Update Catalog website.

Available	Next Step
Yes	This update will automatically sync with Windows Server Update Services (WSUS) if you configure Products and Classifications as follows:Product: Windows 10Classification: Security Updates

If you want to remove the LCUTo remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command:DISM /online /get-packages.Running Windows Update Standalone Installer (wusa.exe) with the**/uninstall **switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.

File informationFor a list of the files that are provided in this update, download the file information for cumulative update 5041578.For a list of the files that are provided in the servicing stack update, download the file information for the SSU (KB5041577) - version 17763.6174.