I think ssh has been scrutinized by hackers already. Vulnerabilities I know about have to do with servers using deprecated encryption algorithms. Firewall rule

I think ssh has been scrutinized by hackers already. Vulnerabilities I know about have to do with servers using deprecated encryption algorithms. Firewall rules in front of ssh are a good idea but I don’t think that adds security to ssh itself. It does block apps opening ports, as you point out.