I'm setting up a Linux server that will run only two services: ssh and httpd.
Some of the security books I've been reading mention backchannel attacks, where the cracker runs a client (like telnet, ftp, an xterm, etc) back from the server host to his machine.
Can the likelihood of backchannel attacks be decreased using a host-based firewall (in my case, using kernel-level packet filtering) to do egress filtering?
TIA.