How to Secure Your .NET Core APIs

Learn best practices for robust web security

9 min readNov 12

Hello everyone! I’ve decided to dive deep into the topic of API security in .NET Core, a subject that, admittedly, I often approach last when developing my APIs.

This hesitation usually comes from uncertainty — have I overlooked something crucial? It’s easy to feel like you’re playing catch-up, ensuring every potential vulnerability is covered.

So I decided to break down the whole thing down, making sure even beginners can understand it. Let’s dive in!

Understanding C# .NET Core API Security

Think of APIs as bridges connecting different parts of a web app.

Just like any busy bridge, there’s always a risk of unwanted visitors. In our case, these are hackers who love to exploit any weak spots.

Since C# .NET Core is widely used for building these bridges, it’s super important to guard them.

Common Risks

SQL Injection: This is like someone slipping a sneaky note to your database, tricking it into spilling secrets or causing chaos.
Cross-Site Scripting (XSS): Imagine if someone could put words in your mouth. XSS is similar; hackers can put their own script into your website, causing harm to your users.
Cross-Site Request Forgery (CSRF): Here, hackers trick users into doing things on your site without them knowing. It’s like forging a signature on an online form.

Now that we know what we’re up against, we can start building our defenses.

Implementing HTTPS

Let’s talk about something crucial yet often overlooked — implementing HTTPS in our C# .NET Core APIs.

It’s a bit like putting a lock on your front door. Sure, it’s basic, but it’s essential for keeping your house safe. HTTPS does just that for your data.

In simple terms, HTTPS encrypts the data traveling between your user’s browser and your API. It’s like sending a secret letter that only the sender and receiver can read.