Microsoft releases KB4594442 Out-of-band patch (OS Build 17763.1579)

Microsoft has issued a new update for Windows 10, version 1809. It comes out-of-band, and fixes a critical vulnerability in Windows 10 'October 2018 Update'.

The change log for the patch notes the following.

What's new in KB4594442 (Build 17763.1579)

Addresses issues with Kerberos authentication related to the PerformTicketSignature registry subkey value in 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.

Also, it includes a  known issue.

Known issues

After installing KB4493509, devices with some Asian language packs installed may receive the error, "0x800f0982 - PSFX_E_MATCHING_COMPONENT_NOT_FOUND."

Microsoft offers the following workaround.

1. Uninstall and reinstall any recently added language packs. For instructions, see Manage the input and display language settings in Windows 10.
2. Select Check for Updates and install the April 2019 Cumulative Update. For instructions, see Update Windows 10.

Note If reinstalling the language pack does not mitigate the issue, reset your PC as follows:

1. Go to the Settings app > Recovery.
2. Select Get Started under the Reset this PC recovery option.
3. Select Keep my Files.

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