Shortly after Microsoft pushed an emergency security update to patch the PrintNightmare exploit, some users on the /r/sysadmin subreddit reported that their customers’ printers stopped working. It’s an unfortunate development, given that Microsoft’s patch does not fully resolve the PrintNightmare vulnerability.
Most of the printers affected by this security update are actually Zebra label printers, which are often found in business or industrial settings. Microsoft has acknowledged this issue, and suggests that those impacted either roll back to a previous version of their Windows operating system or reinstall the printer under administrative privileges.
A future update will address the new bug, but in the meantime, people are left to fix it on their own. Because this bug mostly impacts Zebra printers, system admins and IT workers may need to spend the next few workdays rolling back Windows updates or reinstalling printers one at a time.
Funny enough, PC users and system admins dealt with a similar bug earlier this year. A Windows update pushed in March caused PCs to crash when connected to printers, specifically models from Kyocera, Zebra, Dymo, and Rico.
Microsoft still suggests that people download the emergency update, as PrintNightmare can give hackers full control over personal computers and large networks. That said, researchers have already found ways to bypass the patch, so it is not a be-all-end-all solution to PrintNightmare.
Source: r/sysadmin via The Verge