MariaDB Server 10.4 came with a whole lot of Security related changes. Some of them are merely optimizations (like MDEV-15649), some improve existing features to be more robust (MDEV-15473, MDEV-7598) or convenient (MDEV-12835, MDEV-16266). Some are MySQL compatibility features, requested by our users (MDEV-7597, MDEV-13095).
But the first thing any MariaDB Server user, whether an experienced veteran or a newbie, does — before even issuing the first SQL statement — is logging in. Authenticating to the database server. Read more