If you’re getting Internal server error all over the places on your websites on a cPanel server and PHP is configured to run as suphp CGI mode, then you might be observing the following error on error_log due to ModSecurity. It might be searching for the sticky/suid permission on suphp binary:
SecurityException in Application.cpp:188: Do not have root privileges. Executable not set-uid
To quickly get this fixed on your cPanel server execute the following command:
chmod +s /opt/suphp/sbin/suphp
This should fix the issue instantly.