By default, PHP will tell the world what version of PHP you are using, e.g.
X-Powered-By: PHP/5.3.8
To fix this you can either change php.ini:
expose_php = off
Or change the header:
header("X-Powered-By: Magic");
Or if you'd prefer a htaccess method:
Header unset X-Powered-By
If either of the above methods do not work, there is also the header_remove()
function that provides you the ability to remove the header:
header_remove('X-Powered-By');
If attackers know that you are using PHP and the version of PHP that you are using, it's easier for them to exploit your server.