After you’ve changed the default username and password on our Raspberry Pi or BeagleBone Black, the next step to securing it is to install and configure a firewall. A firewall will help keep your device secure by limiting or block connections to the services running on your device, creating a far smaller attack surface that can be exploited.
When you start using a Raspberry Pi or BeagleBone Black, it comes with a default username and password. While this makes it easy to log in and get started, it also makes it easy for anyone to log in. We should probably do something about that. Luckily this isn’t very hard to fix, you just need to create a new account and disable the default account.