PaperCut Software says an unspecified PaperCut NG/MF vulnerability is under active attack, with confirmed customer incidents and a warning that the Application Server should not be reachable from the public internet. PaperCut NG manages printing; PaperCut MF extends that control into multifunction copiers and their touchscreens.
The risk is not just to the server itself. PaperCut’s Application Server is the control point for the print-management plane, so if an attacker reaches it, they can drive copier functions and potentially pivot into the embedded interfaces on the devices it manages.
That makes exposed PaperCut servers a boundary problem, not a routine server patch issue. For organizations that let the web interface face the internet, the exposure can extend from a single management host to the physical office devices hanging off it, and the vendor says it is still investigating what specific flaw is being used.