Microsoft’s current out-of-band KB5004945 PrintNightmare safety updates are stopping Home windows customers from printing to sure Zebra printers.
Final month, a PoC exploit for a brand new Home windows Print Spooler distant code execution and native privilege escalation vulnerability referred to as PrintNightmare was by chance disclosed on GitHub.
Quickly after, Microsoft acknowledged that it was actively exploited, and an unofficial 0Patch micropatch was released to briefly repair the vulnerability.
This week, Microsoft released mandatory out-of-band Windows security updates to repair the distant code execution part of the PrintNightmare vulnerability.
Nevertheless, researchers rapidly decided that these patches did not fix the vulnerability in all circumstances.
Sadly, the patches are additionally inflicting printing points for some Home windows customers.
Safety replace causes printing points
“We now have about 1000 prospects utilizing Zebra printers and are getting flooded with calls from them not with the ability to print. This replace is the offender for positive as rolling it again has issues spitting out once more immediately,” an affected individual posted to the Sysadmin subreddit.
Quickly after, many different Zebra house owners confirmed that they too had been having points after putting in the replace.
In response to customers affected by the bug, it’s only affecting printers immediately connected to Home windows gadgets by way of USB. Zebra printers hooked as much as a print server are usually not affected.
Home windows customers additionally report that solely particular Zebra fashions are affected, with LP 2844, ZT220, ZD410, ZD500, ZD620, ZT230, ZT410, and ZT420 being a number of the identified fashions affected by the patch.
After uninstalling the safety updates, customers state that the printers start to work high-quality once more. As it is a necessary safety replace, after a while, Home windows will robotically reinstall the replace.
It’s unclear what’s inflicting the problem, however the safety replace replaces the localspl.dll file with a brand new modified model. Modifications on this DLL could also be conflicting with the Zebra printer drivers and stopping printing.
For these affected, you possibly can briefly prevent this update from being installed again, however it’s crucial to find out if printing is extra essential than the dangers of the vulnerability.
BleepingComputer has reached out to Zebra about this concern however has not heard again presently.