Huh? execve(2), of course, lets to execute arbitrary files. No need to spawn a tty at all. https://swisskyrepo.github.io/InternalAllTheThings/cheatshee...
>This is all that would be relevant, and this is also very rare.
Huh? Exploiting an unpatched vulnerability on a server to get access to a user account is.. very rare? That's exactly what lateral movement is about.