> Zero-click describes an issue on a client system where usually a user would have to click something to trigger it, but doesn't as parsing/processing happens before the user actually sees anything (e.g. via an SMS on a phone).
Historically these have been referred to as RCE.
FWIW You are essentially describing a service listening on the network. It’s silly to try to make an artificial distinction based on some irrelevant L4 differences.
Client services with zero interaction, have traditionally been regarded as safer, usually for client side attacks we'd expect a trigger from user action (e.g. a link being clicked, a PDF file being opened).
Just because you don't find something to be useful as a distinction in your line of work doesn't necessarily mean that it's not useful to anyone ...
iMessage isn’t meaningfully different from Apache, instead of listening on a TCP number it listens on your Apple user id.
From any useful perspective, RCE and zero-click exploits are the same thing. The latter is just a fancy name for the moron journalists like the one who wrote this article to bandy about to lure in some readers.
RCE occurs on a system with a listening daemon/service (e.g. web, SQL, DNS SSH).
Zero-click describes an issue on a client system where usually a user would have to click something to trigger it, but doesn't as parsing/processing happens before the user actually sees anything (e.g. via an SMS on a phone).