Hi...The problem with CGI scripts is that each one presents yet another opportunity for exploitable bugs. CGI scripts should be written with the same care and attention given to Internet servers themselves, because, in fact, they are miniature servers. Unfortunately, for many Web authors, CGI scripts are their first encounter with network programming.
CGI scripts can present security holes in two ways:
They may intentionally or unintentionally leak information about the host system that will help hackers break in.
Scripts that process remote user input, such as the contents of a form or a "searchable index" command, may be vulnerable to attacks in which the remote user tricks them into executing commands.
CGI scripts are potential security holes even though you run your server as "nobody". A subverted CGI script running as "nobody" still has enough privileges to mail out the system password file, examine the network information maps, or launch a log-in session on a high numbered port (it just needs to execute a few commands in Perl to accomplish this). Even if your server runs in a chroot directory, a buggy CGI script can leak sufficient system information to compromise the host.