So to elaborate. Many Internet facing systems are application servers (e.g. web servers). They typically have very few local users, administrative/Ops staff are the primary users.
At that point an attack requiring the ability to execute arbitary code on the host as a local user is possibly less relavant as, if an attacker is in that position, they likely have a number of other options to further their goals.
The reason I made the comment about alternate controls, is that the original discussion and point I was making revolved around Internet focused attackers, rather than local attackers, so it's not too surprising that I didn't try to cover that case :) No sinister intent, honest!
Heck however if we want to then lets theorize that I can just use some form of firewall to port forward the high port that's presented externally to 22/TCP internally to get the best of both worlds, both a less visible external service and an internal port that requires root to bind.
At that point an attack requiring the ability to execute arbitary code on the host as a local user is possibly less relavant as, if an attacker is in that position, they likely have a number of other options to further their goals.
The reason I made the comment about alternate controls, is that the original discussion and point I was making revolved around Internet focused attackers, rather than local attackers, so it's not too surprising that I didn't try to cover that case :) No sinister intent, honest!
Heck however if we want to then lets theorize that I can just use some form of firewall to port forward the high port that's presented externally to 22/TCP internally to get the best of both worlds, both a less visible external service and an internal port that requires root to bind.