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by lino767

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What is the risk of having port # 21, 139,135,1025,445 open? My freind connected to airport wireless and sent me the mentioned port numbers and told me if I have those ports somebody can get acces cause problem + this is what he said tom me "A few of the ports are extremely serious they cause DOS (Denial of Service) attacks which will bring a network to it's knees"

What do you guys think?

Thank you,

4 replies

by jmgarvin

First check out http://www.sans.org/top20/ This is the top 10 problems of Windows and *nix.

Port 21 FTP: Just don't allow annon logins and make sure that you use a good ftp daemon.

Port 139 NetBIOS: There is no reason to have this open to the outside world. This is a security threat and you should close it to all but your intranet.

Port 135 DCE Endpoint: I'm not sure why you need this open to the outside world. I am also not aware of any reason that you machine needs to have this open either for cable or DSL. I could be wrong, but you don't need this open as far as I know.

Port 1025 Network Blackjack: You don't need this open to the outside world.

Port 445 MS DS: You don't need this open either.

I don't know why you have the ports open, but you don't need them to be open. You typically need:

Port 21 FTP - Egress/Ingress (for server)
Port 80 HTTP - Egress/Ingress (for server)
Port 443 HTTPS - Egress/Ingress (for server)
Port 110 POP3 - Ingress
Port 143 IMAP - Ingress

I think you should probably lock down your firewall only allow established connections and go from there.

by lino767

My buddy picked up the mentioned ports by scanning other laptop in the air port. Does this mean the connection he had in the air port is not secured or the laptop he scanned is not secured?

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