My app worked perfectly… until I discovered my database was open to the entire internet.
Everything was working. The application was live, users could sign up, and data was being stored without any issues. From the outside, it looked like success. But behind the scenes, it was a disaster waiting to happen.
The system itself was simple: a web application running on a Virtual Machine, a backend API handling requests, and a database storing user information. Everything deployed smoothly. There were no errors, no warnings—just a working system.
Like many beginners, I assumed that if it worked, then it was fine. That assumption turned out to be dangerously wrong.
What I didn’t realize at the time was that my database was exposed to the internet. There were no restrictions, no isolation, and no protection. It was simply sitting there, reachable by anyone who knew where to look.
It didn’t take long before something did.
An automated bot scanning the internet found the open port. There was no sophisticated attack involved—just a simple scan. It connected without resistance.
At that moment, everything was already compromised. User data, emails, and passwords were all accessible. There were no alarms, no warnings, and nothing visibly broke. The application kept running as if nothing had happened, but the damage was already done.
That’s when it hit me—the problem wasn’t my code or my deployment. It was my network.
I had focused on building the application, but I completely overlooked the environment it lived in. Everything was public and exposed. In the real world, that’s not just a mistake, it’s an invitation to attackers.
The system should have been structured differently. The web app could remain public, but the API should have had controlled access, and the database should have been completely private. Only the application should communicate with the database, not the internet.
This is exactly where Virtual Networks (VNets) come in. A VNet creates a private space in the cloud where you control what is exposed and what remains hidden. It allows you to define who can access your resources and how they interact. Without it, you’re essentially leaving your infrastructure open.
The truth is, systems don’t get compromised because they are complex. They get compromised because something was left open.
DevOps is not just about making things work; it’s about making sure they are secure and resilient. Virtual Machines run your applications, but Virtual Networks protect them. Without proper network isolation, you’re not building systems—you’re exposing them.
