Mitrastar GPT-2741GNAC-N2 devices are provided with access through ssh into a restricted default shell.The command "deviceinfo show file" is supposed to be used from restricted shell to show files and directories. By providing " /bin/sh" (quotes included) to the argument of this command will drop a root shell.
https://gist.github.com/geraldog/2d07fdedbbb79d822e9df4b75f882a63