“One of the great things about linux is that you can connect to
your machine remotely and administrate it, use it, etc. Of course
tools to do that have existed as long as unix itself has existed.
Telnet, rlogin, rsh, rexec, X all do a great job of letting you
access your machine and get things done.”
“Those tools worked great until the advent of the first packet
sniffer. Packet sniffers are simple programs that run and decode
network traffic. Typically they look for particular bytes in the
network stream like ‘Password:’ or ‘authentication’ or ‘login’ and
then grab all the bytes after that string: Your password or
authentication token. With large networks and vast numbers of
machines out there today, there is no telling where a sniffer could
be running.”
“There are several ways to prevent this from ruining your day
(and letting a cracker into your machine).”