The web service on Epson WorkForce WF-2861 10.48 LQ22I3(Recovery-mode), WF-2861 10.51.LQ20I6, and WF-2861 10.52.LQ17IA devices allows remote attackers to upload a firmware file and reset the printer without authentication by making a request to the /DOWN/FIRMWAREUPDATE/ROM1 URI and a POST request to the /FIRMWAREUPDATE URI.