I will make a reservation, I am mediocre in Linux systems. I have several Raspbian (Client) devices that have access to the network over LTE (IP over NAT). I have my own server under Ubuntu (server). I plan to automatically run a script on the "client" to forwarding a port via SSH, and for this I created a user without a shell on the "server" (user_123). If the "client" device is opened, you can find "user_123" and the password there. Question - is it possible, knowing this data, to damage my "server"? And what is the safer option? My main goal is to connect via SSH to my devices. This is my algoritmus:
-On server.
$ sudo useradd -s /bin/false user_123
$ sudo passwd user_123
-On device.
$ ssh -fN -R 10022:localhost:22 user_123@serverIp
-On server.
$ ssh -p 10022 device_user@localhost