Block Connections to Insecure Services Running on Unprivileged Ports

• SOCKS - TCP port 1080

• NFS - UDP and TCP port 2049

• X Windows - TCP ports 6000-6063

• portmap - UDP and TCP port 111

• Connections from clients bound to these ports should be allowed.

• Connections to servers on these ports should be blocked - i.e. packets with one of these as the destination port, the SYN flag set, and the ACK flag cleared.

Notes: