Some network admins are reporting that this week’s Windows 10 updates break network printing. The latest updates include the final fixes for PrintNightmare. Originally reported in July, the vulnerability gives attackers a means of gaining admin-level privileges remotely through the point and print service.
Microsoft quickly rolled out updates but was unable to fully fix it. Now, the latest updates rolled out this week seem to have made things worse. Some admins are unable to print at all via networked printers, and the only solution they’ve found is to undo the updates. It goes to show how convoluted the problem is and how complex it is to find a complete solution.
Security researcher Benjamin Delpy says this happened because the fix disabled the CopyFiles directive print driver feature. It can be reactivated by setting the HKLM\Software\Policies\Microsoft\Windows NT\Printers registry key to “1,” but doing so may make a device vulnerable again. The issue does not seem to be manufacturer specific, and although the errors being reported by various users may be different, the end results are all the same.
Some real network printers can no longer be installed after the tuesday patch.
— Brute Bee (@BruteBee) September 16, 2021
Screenshot from someone in Brazil, pic.twitter.com/RuGkuV0aP6
The problem has happened for us on different sites. The print servers were 2012R2 and 2016. All worked fine before the update…
After yesterday’s Windows Update, none of the network computers can print to Windows 10 computer we use as a print server…
As far as I know, this affected both printers with v3 and v4 drivers, but I’m not 100% sure (this issue was different from the issue emerged with the previous update which broke v3 printers). After uninstalling the patch on the server everything got back to normal…
Source: Bleeping Computer