Windows Server January Update Prevents Netlogon Secure Channel Connections

Microsoft has confirm the security issue introduced by January updates

Security updates introduced by Microsoft on January 11, 2022 may cause problems with Windows Server. After installing these updates, certain applications or devices may no longer be able to establish a Netlogon secure channel connection with Windows Server.

In a statement, Microsoft has confirmed this problem. They explained that Windows clients are not affected, only devices running Windows Server 2008 SP2 and newer are susceptible to the problem.

A full fix is in progress

"After installing KB5009555 or any updates released January 11, 2022 and later on your domain controllers, scenarios which rely on Read-only domain RODC accounts must have a linked and compliant KRBTGT account to successfully establish a Netlogon secure channel. Affected applications or network appliances, such as Riverbed SteelHead WAN Optimizers, Affected applications or network appliances, such as Riverbed SteelHead WAN Optimizers, might have issues joining domains or limitations after joining a domain."

Investigations are continuing and a full fix is in the works, but there is no firm timeline for when it will be released to users, as updates from developers or manufacturers are needed to handle the whole thing. "Affected apps and network appliances will need an update from their developer or manufacturer to resolve this issue. Microsoft and Riverbed are presently investigating and will provide an update when more information is available.” explained Microsoft.

For users who have already upgraded and are experiencing the issue, the only solution seems to be deleting the said patch completely, but on the other hand, by removing the update, you will also lose all the security improvements it deployed on your computer. So it is still recommended to wait for an official solution.