You can use following steps to check the server for suexec
1) Login into you server as root and fire following command
If server is Suexec then result would look like
DEFAULT PHP: 5
PHP4 SAPI: suphp
PHP5 SAPI: suphp
2) If you are not sure about Shell then you can also check the SuExec is enabled or not? from your WHM.Lgin into your WHM and in the menu find Configure PHP and SuExec
Check the drop down box for “PHP 4/5 Handler” – and if beside that it says “suPHP” – Then your sever is SuExec enabled
3) If you don’t have root access, you can create a php file (test.php) in your account from cPanel >> File Manager and change the permissions on that file to 777 and open it in a browser. If it gives 500 Internal Server Error, your most probably running suPHP.
4)As well as you can also create the phpinfo page in your account from your cPanel >> File manager For ex. phpinfo.php with the following code;
<? phpinfo() ?>
After creating phpinfo.php page browse it http://yourdomainname.com/phpinfo.php and if it shows
Server API = Apache then server is not running PHP in Suexec mode
Server API = CGI the server is running PHP in Suexec mode.