How do hackers take advantage of open ports as a vector for an attack?

[Ethio Cybrary]

How do hackers take advantage of open ports as a vector for an attack?

[chrizree]

Well, it depends on what's behind that open port

[NoExecute]

It's not the open port alone, that's not enough :)

It requires something that listens / answers on that port, and that service have to be misconfigured, or exploitable for it to be used as an attack vector.
But, of course it also needs to be open, for something to go through to the service, and the firewall have to allow outbound connections back :)