API Security: A key to avoiding cyberattacks

In technology, there are different ways to refer to communication between two systems. Through an API, a mobile or web app connects to the server side of an application and simplifies the software’s client-side interaction.

But, what do we mean when we talk about API Security? This term focuses specifically on current online APIs and comprises access control, API privacy, API reverse engineering, and vulnerability exploitation prevention.

Since APIs are freely available via public networks and frequently well-documented or easy to reverse-engineer (accessible from anyone), they are good fraudster targets since they're vulnerable to DDoS attacks. Also, taking into account that bypassing the client-side application might be used to disrupt service or get unwanted access to sensitive data, API security prevents harm from unauthorized queries.

Why is API Security so important?

API security is key to keeping any system safe because it protects data sent over an open network between clients and servers and combines data and services.

When an API is misused, exposed, or hacked, sensitive data is at risk. In order to avoid this, there had to be adequate back-end security. If there’s an insecure API, hackers may take this advantage and attack with DoS for example. Also, they can scrape APIs and violate use limitations.

This is why protecting APIs is vital in this age of ubiquitous connection: considering that APIs are needed for every business application, if there’s any misconfiguration advanced attackers can introduce malicious code to access sensitive data or compromise the system's backend.

Methods to Check the Safety of an API

To manually check for security holes in your APIs, you may use the following approaches:

Test for Parameter Tampering

Parameters supplied in API queries are often easy to manipulate. Attackers may modify the price of a transaction and get the goods for free by tampering with the parameters, or they may deceive an API into revealing private information without the user's permission.

Hidden form fields are often used for parameter manipulation. The element inspector in your web browser may help you check for remote areas. Try out various values for any hidden fields to observe how your API responds.

Test for Command Injection

Injecting OS commands into API inputs is an excellent way to see whether your API may be exploited through command injection attacks. Using the command file in the /usr/bin/ls directory if your API server is running Linux. It's best to use a command in the server's OS that won't do any damage and that you can see in action, like a reboot.

Test for API Input Fuzzing

To "fuzz" an API, you feed it nonsense data in the hopes of finding a bug in the functionality or security of the API. It's essential to check for clues that the API gave an inaccurate response, mishandled inputs, or crashed.

If your API takes numbers as input, you may attempt very big or small numbers, negative numbers, or even zero. You may experiment with non-text characters, random SQL searches, and system commands if it takes strings.

Test for Unhandled HTTP Methods

Many different HTTP methods can be used by web apps when interacting via APIs. We can use these HTTP methods to save, delete, and retrieve information. You will most likely encounter an error if the server does not recognize the HTTP protocol. Of course, this is only sometimes the case. The server's lack of support for the HTTP method is a potential security hole.

Making a HEAD request to an API endpoint that requires authentication is an efficient way to determine whether the server supports a particular HTTP method. Test all HTTP verbs, including POST, GET, PUT, PATCH, and DELETE.

Having secure APIs is a complex work that should be done carefully. If you want to know more about building APIs Securely, download our free ebook.