

TBH, it sounds like you have nothing to worry about then! Open ports aren’t really an issue in-and-on itself, they are problematic because the software listening on them might be vulnerable, and the (standard-) ports can provide knowledge about the nature pf the application, making it easier to target specific software with an exploit.
Since a bot has no way of finding out what services you are running, they could only attack caddy - which I’d put down as a negligible danger.
Eternity is a loooooong time