Some services run really good behind a reverse proxy on 443, but some others can really become an hassle… And sometimes just opening other ports would be easier than to try configuring everything to work through 443.
An example that comes to my mind is SSH, yeah you can use SSLH to forward requests coming from 443 to 22, but it’s so much easier to just leave 22 open…
Now, for SSH, if you have certificate authentication or a strong password, I think you can feel quite safe, but what about other random ports? What risks I’m exposing my server to if I open some of them when needed for a service? Is the effort of trying to pass everything through 443/80 worth it?
Be sure to keep everything up to date too. Even openssh has had multiple vulnerabilities just this year.
Always good advise
However, OpenSSH is pretty solid security wise. https://www.openssh.com/security.html
Note: it is best to check the official security pages instead of random websites.
Vendors packaging OpenSSH open up even more vulnerabilities that the devs of OpenSSH can’t protect you from. See the recent xz poisoned OpenSSH packages