Any port listening and wanting to make a connection must do so with the permission of the user and firewall. If not what case would a socket connect with out permission of firewall or user?
A passive OPEN request means that the process wants to accept incoming
connection requests rather than attempting to initiate a connection.
Often the process requesting a passive OPEN will accept a connection
request from any caller. In this case a foreign socket of all zeros
is used to denote an unspecified socket. Unspecified foreign sockets
are allowed only on passive OPENs.