Suppose I bought a domotic IOT device which connects to the internet via an ADSL modem and permits access to it via web browser or smartphone app without SSL encryption and several other weaknesses.
I need to use it because it's an essential piece of my home but need to secure it as soon as possible.
Is there any way to put a routing/firewall device in between the IOT device and the Modem such that I can securely authenticate to the routing/firewall device first and from there access the unsecured device.
What is the name of such configuration and how would it work? Notice a VPN itself is not enough because the smartphone app might not support it.
Are there canned solutions to problems like these? How can one protect essentially vulnerable internet facing devices from Shodan scans without changing the vulnerable devices but essentially wrapping them in a secure environment?