Hello,
 
Are you asking how to prevent cgi-bin files from seeing the system?
 
There are a few things you can do, in varying levels of difficulty.
 
1) The simplest, and the one I recommend would be to secure the user home directories with the secure_access_group method:
http://www.directadmin.com/features.php?id=961
 
this makes it so that files for each user cannot be seen by other Users.
 
2) The more complex, but complete solution is to jail the cgi-bin files, but that takes up a huge amount of space, is far more complex and has a higher likelyhood of not working due to it's complexity.
Also, it's classified as beta, and likely will remain there, as development on it has ceased.
http://help.directadmin.com/item.php?id=90
 
 
3) Other various security tips, not directly related to your question:
http://help.directadmin.com/item.php?id=247
 
 
If you don't want to allow cgi-bin access at all (easiest solution), type:
chmod 0 /usr/sbin/suexec
 
to enable it again, type:
chmod 4755 /usr/sbin/suexec

Thank you,
 
John
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