One of the “must do’s” on setting a secure apache web server is to disable directory browsing.
Usually apache comes with this feature enabled but its always a good idea to get it disabled unless you really need it.
Usually it will be located in path like this: /etc/apache/httpd.conf.
To edit this file you will need root access to your server.
Using some file editor like Vim or Nano open this file and find the line that looks as follows:
Options Includes Indexes FollowSymLinks MultiViews
then remove word Indexes and save the file. The line should look like this one:
Options Includes FollowSymLinks MultiViews
After it is done, restart apache (e.g. /etc/init.d/apache restart).