Improper input sanitization within the restricted administration shell on UCOPIA Wireless Appliance devices before 4.4.20, 5.0.x before 5.0.19, and 5.1.x before 5.1.11 allows authenticated remote attackers to escape the shell and escalate their privileges by uploading a .bashrc file containing the /bin/sh string. In some situations, authentication can be achieved via the bhu85tgb default password for the admin account.