Microsoft releases Update KB4594440 Windows 10 build 19042.631

Improvements and fixes:

This non-security update includes quality improvements. Key changes include:

  • This build includes all the improvements from Windows 10, version 2004.
  • No additional issues were documented for this release.
  • Addresses issues with Kerberos authentication related to the PerformTicketSignature registry subkey value inĀ CVE-2020-17049, which was a part of the November 10, 2020 Windows update. The following issues might occur on writable and read-only domain controllers (DC):
    • Kerberos service tickets and ticket-granting tickets (TGT) might not renew for non-Windows Kerberos clients when PerformTicketSignature is set to 1 (the default).
    • Service for User (S4U) scenarios, such as scheduled tasks, clustering, and services for line-of-business applications, might fail for all clients when PerformTicketSignature is set to 0.
    • S4UProxy delegation fails during ticket referral in cross-domain scenarios if DCs in intermediate domains are inconsistently updated and PerformTicketSignature is set to 1.

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