Edit the php.ini file:

sudo vi /etc/php5/apache2/php.ini

Add or edit the following lines an save:

<file bash /etc/php5/apache2/php.ini> disable_functions = exec,system,shell_exec,passthru register_globals = Off expose_php = Off display_errors = Off track_errors = Off html_errors = Off magic_quotes_gpc = Off mail.add_x_header = Off session.name = NEWSESSID </code>

Restart Apache server. Open a Terminal and enter the following:

sudo service apache2 restart