Contemplate this, a one-time colleague wrote a CGI that had once had an upload feature in it, the code was taken out, but his temp directory was in fact the cgi-bin directory. Someone who recognised the cgi (it was foolishly placed on a CGI download site) knew that he could upload a script to replace one that was already in the directory - but no longer used. Can you see where I am going! Somebody did just that, they uploaded a script, then they uploaded another, called them innocuously from the browser and siezed control of the machine, looked in the code for the original CGI, got the info for the database, downloaded his entire database (about 2 million records) and then proceeded to delete the database and then force a backup (another of the CGI's functions) that cleared his backup of data as well. By the time he got to the office the next day it was all over. The company went belly up and he along with it.
PROTECT YOURSELF FROM UPLOADS!
I learned a lot about CGI security from that experience.