[floatingatoll]

It’s certainly no less safe than the backdoored-for-decades phone/fax networks used by medical professionals to discuss medical secrets with patients and send prescriptions to pharmacies. It’d be nice if it was more safe, but it’s hard to sink lower than a telco line.

[lvh]

You can send faxes to someone without the telco running a local webserver on your fax machine, and you don't run thousands of other applications on your fax machine, and your fax machine doesn't usually come with a nifty record feature, nor a camera and a microphone.

[floatingatoll]

I hesitate to point this out, but quite a lot of fax machines come with a microphone.

(And, noting the prevalence of articles from a few years ago talking about "update your fax machine firmware", I suspect you could fuzz their telco line-parser for very interesting results!)

[lvh]

Good point--you're talking about the embedded handset or something else? That said, as you hint at: not quite the same thing from a threat model perspective :)

[floatingatoll]

Indeed!

That depends entirely on whether the handset is physically disconnected by the on-hook switch, or if a firmware exploit could remotely enable it.

Threat modeling a fax machine in the era of fuzzing-RCEs is a particularly interesting thing to consider.