"The infinite recursion problem with aliases closely
parallels a very simple exploit that can be run in a simple shell
script. The ends are the same, and the means are closely related.
For instance, if you create a shell script called "ls," with the
"and manage to get that in a user's PATH before the real /bin/ls
(or /usr/bin/ls), it'll ratchet up the number of open processes and
filehandles very quickly. If let sit, it will take down any machine
of any size eventually."