The HTTP web-management application on Edgewater Networks Edgemarc appliances has a hidden page that allows for user-defined commands such as specific iptables routes, etc., to be set. You can use this page as a web shell essentially to execute commands, though you get no feedback client-side from the web application: if the command is valid, it executes. An example is the wget command. The page that allows this has been confirmed in firmware as old as 2006.