Of course, there are no security provisions whatsoever. If you can get a device on the LAN, you're golden. Every device, fully open to monitoring and control of every attached piece of equipment.
In the new world of inexpensive, battery powered LoRaWan to Ethernet bridges with tens of kilometers range, I can't even begin to imagine the industrial carnage we're heading for. A sufficiently funded attacker could find ways to implant remote monitoring and control in virtually every facility, where they can get a minimum-wage cleaning staff member hired. That means -- pretty much every facility (short of military, perhaps).
Exciting times.
Anyway, what the LoRa did emphasize is that both the network layer and application layer are encrypted with different keys using AES. This means someone would have to compromise both layers to actually control the devices.
Buuut, given that both encryption keys are stored on the device, I bet someone will just walk up with a chip clip and read the keys right out of EEPROM and then the pretty lights will start.
Or they'll just hack the application servers. I've seen some really god awful pieces of software in use.
A vendor once told me "it's so easy to admin our device over the internet. Just go to 192.168..." And of course due to corporate politics we still bought that piece of shit.
Usually keys are stored in a part that is not accessible directly, think of SIM and bank cards. Actually lots of LoRaWan use SIM cards.
/deploying CAN bus without security
That if you have a box that can talk to network A and B, suddenly anything on A can talk to anything on B.
A CAN bus, or older modbus installs, would be airgapped by its very nature.
Using Modbus may be insane, but Internet Protocol (IP) predates it by 5 years.
The original Modbus was designed to communicate with factory devices controlled by logic controllers over serial and eventually over a custom token ring network. Modbus got moved to TCP at some point when I stopped paying attention. Modicon rejected TCP when I was there because the OSI model 7 layer network stack was going to be the next big thing.