For example, where does the VPN connect to? The vendor? Do you trust the vendor more than the internet. Sure. Do you trust the vendor, that does not manage the firmware of their devices and uses inbound connections in the first place, enough to put them on a VPN?
How many devices and vendors do you have? How many VPNs can you establish with the existing networking hardware, and how many can you manage without IP clashes etc. IP clashes work both ways, btw. The vendor has to manage this themselves also if all their clients want VPNs.
Retailers are enterprises with 100s of vendors that run on a shoestring. On top, they use a lot of legacy architecture and hardware. They have teams that have a hard time making an architectural decision in the best of times, but even less so under stress. It is probably the same on the vendors side.
In my mind, the correct solution is indeed to deny any inbound connection to the network, now, to prevent further damage.
Incident response is, in order:
1. preparation (failed)
2. identification (done)
3. containment <--- we are here (take offline, put manual rota in place to manage fridge defrost cycles)
4. eradication (VPN, etc)
5. recovery (take it back online, relieve manual rota)
6. postmortem etcThat's a really strong argument for why systems like this need layered security and should not accept incoming connections from the internet at large.
However, we're talking about companies that put unprotected systems on the public network and did nothing about it even after getting three weeks advance warning.
You can lead a horse to water, but ...
I don't know the companies in question here, I'm not European and my EU family lives in France not Belgium or Sweden, but fwiw here in the states a lot of supermarkets are independent grocers or in a sort of formal or quasi-franchise arrangement where it's part of a "chain" but each store is still somewhat or quite decentralized in management when it comes to the physical stuff at the local store. Which is probably a strength in a lot of cases, makes it easier to adapt to local environment faster, but I suspect there's just plain a knowledge/skill/priority mismatch when it comes to IT. That'd also line up with some of the reports on this I read where there was some official central management system, except certain grocery stores just weren't using it?
The components of solutions for this exist and could even be really cheap, we're not talking much bandwidth here. Not hard to imagine even in a independent grocer association or loose franchise system they could tape together an SBC with preconfigured OPNsense or VyOS or whatever on it and a switch and be able to just tell stores "here, plug your freezers into this, access the portal here" as a default and it'd just route all their traffic to the franchise/IGA's management system. Someone still has to secure that of course, but at least it wouldn't be on the open internet.
Places that wanted to could of course do this other ways, I'm just saying that even with the very tight margins grocery stores tend to run on I think it's very doable to do better going forward, just will take some coordination and knowledge building. "The future is already here, it's just not evenly distributed" and all that.
Each to their own… but why do fridges need to be connected to the internet in the first place?