Printers caught in reboot loop after API change causes firmware fail.

Owners of Epson WorkForce, WorkForce Pro, and XP Series printers recently got a rude surprise, as the printers got stuck in a perpetual restart loop. And it quickly became apparent that the cause had something to do with the printers' connection to the Internet.

On the BleepingComputer boards, one Epson owner reported, "Yesterday it just turned off. I'd turn it back on and 30 seconds later it would turn off. I started messing around and turned off my router. The printer stayed on when I powered it up. Turned on my router and as soon as the printer connected to Wi-Fi it would turn off. I'd leave my router on and I disabled Wi-Fi on the printer and the printer stayed on."

Others reported similar experiences.

The affected printers all had one thing in common—they were connected to the Google Cloud Print service. A change in Google's application interface for its cloud service conflicted with the code in the printers' firmware, causing the firmware to crash at startup once connected to the Internet.

The problems with Internet-connected printers have been demonstrated amply in the past, such as when Andrew "weev" Aurheimer exploited publicly accessible Hewlett Packard printers (accessible with the JetDirect interface) to remotely mass-print neo-Nazi propaganda flyers at a number of universities and other institutions. He found the printers by using security researcher Rob Graham's masscan tool to find devices with TCP/IP port 9100 open.
But the Epson problem is also illustrative of the problems inherent in "Internet of Things" (IoT) devices that are dependent on Internet services to operate—services that can cause malfunctions in third-party systems built to use them (as with the Epson printers in this case) or render entire classes of products unusable (as Nest did when it shut down cloud support for the Hub home automation platform). With Google, Amazon, and others pushing new cloud-connected IoT devices for home automation and other tasks, the risks associated with cloud dependencies for everything from printers to home thermostats are sure to increase.

Epson issued a workaround for the printers on December 7, which required customers to turn off their Internet routers and reset the affected printers. In some cases, this meant simply changing printer settings to turn off Google Cloud Print; in others, it meant resetting printers' network settings to default and then reconfiguring them for the local network.

"These steps will suspend Google Cloud Print Services for your printer and should resolve the problem," an Epson representative said in a support FAQ for the workaround. "To resume printing, do not reconnect your printer to Google Cloud Print Services. Epson is working on a solution to this problem; check with us periodically for an update."

Ars reached out to Epson and Google for comment; an Epson spokesperson directed us via Twitter to the support webpage for the problem and promised a followup with further details. Google has not yet responded.