Copy and paste from http://www.apachefriends.org/en/xampp-linux.html
section 'READ ME':
A matter of security (A MUST READ!)
As mentioned before, XAMPP is not meant for production use but only for developers in a development environment. The way XAMPP is configured is to be open as possible and allowing the developer anything he/she wants. For development environments this is great but in a production environment it could be fatal.
Here a list of missing security in XAMPP:
The MySQL administrator (root) has no password.
The MySQL daemon is accessible via network.
ProFTPD uses the password "lampp" for user "nobody".
PhpMyAdmin is accessible via network.
MySQL and Apache running under the same user (nobody).
To fix most of the security weaknesses simply call the following command:
/opt/lampp/lampp security It starts a small security check and makes your XAMPP installation more secure.