Multiple HP LaserJet Pro Printers are printer vulnerable to hackers according to a new advisory posted by the vendor, dubbed as CVE-2013-4807 (SSRT101181) The main issue is with some of the networked printers, having hidden URLs hardcoded in the firmware, which can be accessed without authentication. The vulnerability could be exploited remotely to gain unauthorized access to data. If a printer is WiFi enabled, then the WiFi info can be extracted from using below URL:https://IP_ADDRESS:8080/IoMgmt/Adapters/wifi0/WPS/P1606dn.
Source: https://thehackernews.com/2013/08/hacking-HP-printers-Vulnerability-wifi-password.html