I am bit familiar with ports,port scanning and protocols,
when i started to think deeply about ports,this one comes to my mind
most guys think "hey we got all our ports other than port 80 is closed and we are secured",but i didn't feeled that way,so started to made some search and some sources said that there are some attack vectors available for opening or messing with a remotely closed port,I just wondered,i do want to know more about the working and some theoretical part of this kind of attack vector,if you guys know some method names,articles or links related to this,then feel free to post here....

hope some one will guide me by giving some links or terms for digging...