Seriously, this is extremely mild as far as issues go. There's basically no incentive to fix this problem, because I bet even the people who lost a few pennies of electricity would still prefer the convenience of ollama not having auth.
Plus, that's the worst case scenario, in real life even if some black hat found an exposed ollama service, they have no interest in generating tokens for <insert random LLM here at 4 bit quant> at a slow speed of <50tok/sec.
Don't expose services to the public internet unless they have been battle hardened to be exposed to the public internet, e.g. Nginx as an authenticating reverse proxy.
Even this one would be remedied by not running ollama as root and not have its binaries owned by the user it is running as (though overwriting executables/libraries that are being mmapped as executables is usually not possible), which I hope would be the standard mode of its setup.
Either way my point is that software contains vulnerabilities, especially software that hasn't been hardened to be exposed to the public internet. Exposing it to the public internet anyway is a display of bad judgement, doubly so when the person responsible seems to believe that the worst thing that can happen is someone using the software as intended. Details of specific vulnerabilities are really beside the point here.
Assuming that the happy path is the worst that can happen is simply naive, there's no two ways about it.
But sure, it's always possible to be more innovative about how to go about enabling RCEs, like the log4j case demonstrates..