Microsoft releases 2021-04 Cumulative Update to supported versions of Windows 10
Microsoft has now released a 2021-04 Cumulative Update to each supported version of Windows 10 to fix various problems in the current version. The update includes regular bug fixes and fixes for various security vulnerabilities.
Having said that, every cumulative update released by Microsoft always fixes old problems and brings new problems. Therefore, we do not recommend that you install updates immediately.
If you are pursuing high efficiency and stability, it is recommended to postpone the installation of the latest cumulative update for half a month to prevent other serious problems in the cumulative update from affecting normal use.
- Updates to improve security when Windows performs basic operations.
- Updates to improve security when using input devices such as a mouse, keyboard, or pen.
Improvements and fixes
- Addresses an issue in which a principal in a trusted MIT realm fails to obtain a Kerberos service ticket from Active Directory domain controllers (DC). This occurs on devices that installed Windows Updates that contain CVE-2020-17049 protections and configured PerfromTicketSignature to 1 or higher. These updates were released between November 10, 2020 and December 8, 2020. Ticket acquisition also fails with the error, “KRB_GENERIC_ERROR”, if callers submit a PAC-less Ticket Granting Ticket (TGT) as an evidence ticket without providing the USER_NO_AUTH_DATA_REQUIRED flag.
- Addresses an issue with security vulnerabilities identified by a security researcher. Because of these security vulnerabilities, this and all future Windows updates will no longer contain the RemoteFX vGPU feature. For more information about the vulnerability and its removal, see CVE-2020-1036 and KB4570006. Secure vGPU alternatives are available using Discrete Device Assignment (DDA) in Windows Server LTSC releases (Windows Server 2016 and Windows Server 2019) and Windows Server SAC releases (Windows Server, version 1803 and later versions).
- Addresses a potential elevation of privilege vulnerability in the way Azure Active Directory web sign-in allows arbitrary browsing from the third-party endpoints used for federated authentication. For more information, see CVE-2021-27092 and Policy CSP – Authentication.
- Security updates to Windows App Platform and Frameworks, Windows Apps, Windows Input and Composition, Windows Office Media, Windows Fundamentals, Windows Cryptography, the Windows AI Platform, Windows Hybrid Cloud Networking, the Windows Kernel, Windows Virtualization, and Windows Media.