I work for a large medical device company and my team works on securing medical devices. At least at my company as a general rule, the more expensive the equipment (and thus the more critical the equipment, think surgical robots) the less likely it will ever be connected to a network, and that is exactly because of what you said, you remove so many security issues when you keep devices in a disconnected state.
Most of what I do is creating the tools to let the field reps go into hospitals and update capital equipment in a disconnected state (IE, the reps must be physically tethered to the device to interact with it). The fact that any critical equipment would get an auto-update, especially mid-surgery is incredibly bad practice.
I work for the government supporting critical equipment - not in medical, in transportation sector - and the systems my team supports not only are not connected to the internet, they aren't even capable of being so connected. Unfortunately the department responsible for flogging us to do cybersecurity reporting (different org branch than my team) has all our systems miscategorized as IT data systems (when they don't even contain an operating system). So we waste untold numbers of engineer hours now reporting "0 devices affected" to lists of CvE's and answering data calls about SSH, Oracle or Cisco vulnerabilities, etc. etc. which we keep answering with "this system is air gapped and uses a microcontroller from 1980 that cannot run Windows or Linux" but the cybersecurity-flogging department refuses to properly categorize us. My colleague is convinced they're doing that because it inflates their numbers of IT systems.
Anyway: it is getting to the point that I cynically predict we may be required to add things to the system (such as embedding PCs), just so we can turn around and "secure" them to comply with the requirements that shouldn't be applied to these systems. Maybe this current outage event will be a wake up call to how misplaced the priorities are, but I doubt it.
Have you ever tried to airgap a gigantic wifi network across several buildings?
Has to be wifi because the carts the nurses use roll around. Has to be networked so you can have EMR's that keep track of what your patients have gotten and the Pharmacists, doctors, and nurses can interface with the Pyxis machines correctly. The nurse scans a patients barcode at the Pyxis, the drawer opens to give them the drugs, and then they go into the patient's room and scan the drug barcode and the patients barcode before administering the drug. This system is to prevent the wrong drug from being administered, and has dramatically dropped the rates of mis-administering drugs. The network has to be everywhere on campus (often times across many buildings). Then the doctor needs to see the results of the tests and imaging- who is running around delivering all of these scans to the right doctors?
You don't know what you are talking about if you think this is easy.
Air gap the system with the external world is different from air gap internally. The systems are only update via physical means. And possibly all data in and out is offline like, via certain double firewall arrangement (you do not let direct contact but dump in and out files). Not common but for industrial critical system saw a few big shops did this.
So how does a doctor issue a discharge order via e-prescription to the patients pharmacy for them to pick up when they leave? How do you update the badge readers on the drug vaults when an employee leaves and you need to deactivate their badge? How do you update the EMR's from the hospital stay so the GP practice they use can see them after discharge? How do you order more supplies and pharmacy goods when you run out? How do you contact the DEA to get approval for using certain scheduled meds? I'm afraid that external networks are absolutely a requirement for modern hospitals.
If the system has to be networked with the outside world, who is responsible for physically updating all of these machines, so they don't get ransomware'd? Who has to go out and visit each individual machine and update it each month so the MRI machine doesn't get bricked by some teen ransomware gang? Remember that was the main threat hospitals faced 3-4 years ago, which is why Crowdstrike ended up on everyone's computer: because the ransomware insurance people forced them too.
There is a reason that I am a software engineer and not an IT person. I prefer solving more tractable problems, and I think proving p!=np would be easier than effectively protecting a large IT network for people who are not computing professionals.
One of my favorite examples: in October 2013 casino/media magnate and right wing billionaire Sheldon Adelson gave a speech about how the US and Israel should use nuclear weapons to stop Iran nuclear program. In February 2014 a 150 line VB macro was installed on the Sands casino network that replicated and deleted all HDDs, causing 150 million dollars of damage. That was to a casino, which spends a lot of money on computer security, and even employs some guys named Vito with tire irons. And it wasn't nearly enough.
> Who has to go out and visit each individual machine and update it each month so the MRI machine doesn't get bricked by some teen ransomware gang?
The manufacturer does. As I mentioned in my OP I help build the software for our field reps to go into hospitals and clinics to update our devices in a disconnected state. Most of the critical equipment we manufacture has this as a requirement since it can't be connected to a network for security reasons.
As for discharge orders, etc, I can't speak to that, but that's also not what I would consider critical. I'm talking about things like surgical robots, which can not be connected to a network for obvious reasons, especially during a surgery.
External networks are required but it should be possible to air gap the critical stuff to read only. It’s just that it’s costly and hospitals are poor/cheap
Most of what I do is creating the tools to let the field reps go into hospitals and update capital equipment in a disconnected state (IE, the reps must be physically tethered to the device to interact with it). The fact that any critical equipment would get an auto-update, especially mid-surgery is incredibly bad practice.