Restricting MySQL connections from localhost to improve security

Question

I heard that anyone that knows my MySQL Username and Password can access it, Even if it's listening only to localhost.

Supposing my info is as following:

USER: root PASS: 123456 Host: LOCALHOST (only) 

How is it possible that anyone out there (local) can access it?

Answer 1

If you restrict access from remote hosts to your usernames and passwords then someone won't be able to access the database externally.

You could also configure your firewall to only allow traffic to 3306 (MySQL Default Port) from the localhost machine.

Update

To setup your user so they can only access through LOCALHOST use:

GRANT ALL PRIVILEGES ON *.* TO db_user @'localhost' IDENTIFIED BY 'db_passwd'; GRANT ALL PRIVILEGES ON *.* TO db_user @'127.0.0.1' IDENTIFIED BY 'db_passwd'; 

Also, bind your MySQL server to the local address. You can do this by editing the [mysqld] section of my.cnf:

[mysqld] bind-address = 127.0.0.1 

Answer 2

This is an older question that I stumbled across, but if Darkeden had phpMyAdmin or similar running, anyone can log in to that using valid MySQL credentials.

If it was compromised, then in addition to restricting connections, change all passwords.