MariaDB 10.4 implemented a lot of changes to how security is done. Much of this is invisible to most users with the exception of root. The root user is now able to use socket authentication through the unix_socket plugin. It means that if you are logged in to a Linux system as root, you can log on to the MariaDB server without using a password. Note in the example below, the -p option (for “password”) is not used yet the log on is successful.
[root@linuxputer ~]# mysql -u root
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 408
Server version: 10.11.9-MariaDB-log MariaDB Server
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]>And it’s not just that you don’t need to enter a password. Even if a password is provided, it is completely ignored. In this example, a password – which is invalid – is provided, yet the log on is successful.