The article misses another huge and overlooked issue: there are databases that are not accessed via a public Internet address because they are filtered by a firewall BUT are accessed via the local network because in many VPS services you can connect to all the VMs inside the same region internally. Look at this thread: <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;AskNetsec&#x2F;comments&#x2F;3mqufn&#x2F;how_do_you_secure_your_internal_network_in_a_vps&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;AskNetsec&#x2F;comments&#x2F;3mqufn&#x2F;how_do_yo...</a>