Without a VPC, how do you not expose your Aurora cluster to the world?
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Auror...
Aurora DB clusters must be created in an Amazon Virtual Private Cloud (VPC). To control which devices and Amazon EC2 instances can open connections to the endpoint and port of the DB instance for Aurora DB clusters in a VPC, you use a VPC security group. These endpoint and port connections can be made using Secure Sockets Layer (SSL). In addition, firewall rules at your company can control whether devices running at your company can open connections to a DB instance. For more information on VPCs, see Amazon Virtual Private Cloud (VPCs) and Amazon RDS.
