Weak Default Configuration with default blank password

Per https://mariadb.com/kb/en/mariadb-secure-installation/, If you've just installed MariaDB, and you haven't set the root password, the default password will be blank. It is able to skip the password setting during the "mariadb-secure-installation". In the meantime, the password is still blank.
To improve the security, it is suggested to change the default password to "root" instead of blank password.