UNIX system security has been a subject of intense interest for
many years. The ne plus ultra of system breaking is to have the
super-user execute arbitrary code for the miscreant. The most
common way to do this is to frnd a root-owned set-userid program
that calls the shell and exploit its well-known loopholes to get it to
execute a chosen command frle. Reeds [1983] describes several
variations on this theme.
Other interesting possibilities are to convince someone who