“Our food system is built on outdated, unpatched Linux/WinCE with LTE modems”

Let’s imagine you compromise a telco and get past the hurdle of these tractors not having public IPs, they probably still won’t have any services listening on the network.

If they do have some services listening on the network, that’s probably going to be John Deere’s own software and not e.g. an ancient version of Exim.

Without more information this is just silly clickbait.