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API security is the practice that involves techniques implemented to harden APIs, and patch underlying vulnerabilities to mitigate any form of threat.

Application programming interface (API) usage is prevalent considering how it maximizes user experience on the internet and eases the software development process. It’s a mechanism that facilitates communication between two different pieces of software.

APIs are the protocol behind some of the best integrations you enjoy on the internet. For example, the YouTube API allows bloggers to embed links to a YouTube video on their blogs. The Amazon API optimizes ecommerce sites to increase sales and profit by providing the products available for customers and automating sales, orders and inventory.

Every developer at some point will need an API to enhance the quality of their software and business model—hence it has become an integral part of the software development cycle. However, it has also become a high target for attackers, with Gartner placing it as the leading threat vector in 2022.

Another report also stated that 95% of companies experienced API security incidents in the last 12 months, with API attack influx seeing an increase of 681%. In addition, the cost of API security incidents for businesses has reached about 75 billion USD yearly.

Following the growing rate of API attacks, developers must foster good API security practices. In this article, we’ll explore the concept of API Security and look at 11 best practices to improve your API security level.

What Is API Security?

API security is the practice that involves techniques implemented to harden APIs, and patch underlying vulnerabilities to mitigate any form of threat. Securing APIs refers to ways businesses can prevent an API breach by bad actors or misuse by following a policy or using a security product.

This involves replacing basic authentication methods like usernames and passwords for security tokens and multi-factor authentication to improve access control. With a stricter authentication process for API security, there will be user identity verification processes for validation. Also, authorization processes will restrict users’ access. Other features like encryption and signatures will ensure confidentiality during communication from client-server, while throttling and quotas will prevent attacks that aim to overwhelm systems like DDOS.

API security encompasses implementing features that will ensure confidentiality, integrity and availability by detecting and preventing intrusions.

Learn about adding passwordless authentication to a Next.js app.

Importance of API Security

API security shields your application software from bad actors who employ malicious methods like cross-site scripting, bonnets, MITM, and SQL injection to attempt a breach or disruption on your platform. API vulnerabilities have led to past compromises on big organizations like Facebook, LinkedIn and Salesforce.

Hardening APIs with security tokens, encryption, throttling and API gateway will make the attack surface thinner. Moreso, application test processes are faster. API security scans and spots any malicious program already running in a flash. It also discontinues the process so that it doesn’t further cause damage to your application software. Developers are recommended to test for API security as this will reveal performance level and hardiness, and determine how safe a software can be.

Most Common API Security Risks

The incredible velocity of APIs usage comes with many risks which can lead to a breach of user privacy and disruption of services. These risks vary significantly. Some common API security risks include:

Bad Coding Foundation

A haphazard coding foundation can make your APIs vulnerable. Threat actors can take advantage of inefficient coding foundations to exploit your APIs.

Poor Asset Management

In the rush of designing a new API, developers might do rough documentation while exposing their Beta or old APIs. This can leave attackers the opportunity to leverage these mistakes to wreak havoc.

Exposure to Injection Attacks

APIs can be susceptible to SQL injection attacks when there is poor inspection and validation for the requested data. Attackers can use SQL injection to gain access and run malicious programs with authorization.

No Rate Limit

APIs are used to communicate with other software on your behalf. However, malicious users can exploit your application and send overwhelming requests that can shut down your service if you lack rate limiting.

Bad Authorization Function

A user application process should only have access to the request they make. However, when the authorization function is faulty, users can modify data they’re not supposed to access.

What are the Types of API Security? What Best Practices Should You Implement?

APIs are thoroughly documented and available to everyone on the internet including hackers and bad actors. Thus, they are easy to exploit when no strong security measures exist. The best API security practices have strict policies for authorization and authentication, the primary requirement to prevent API incidents. With API security, you can contain hackers before they can spread their tentacles throughout your software. The best API security practices includes:


Authentication validates the legitimacy of any user sending a request to your API. To verify user identity before allowing access to your API, you can use the rudimentary method, which requires a user to log in with a user ID and password. On the other hand, you can go stricter with the multi-factor authentication method or use tokens. Using tokens means only users whose keys are already in the database will gain access.

You can also activate the OAuth protocol, which allows legitimate users to log in without passwords. With this protocol, there will be no need to protect customers’ data and this will in turn reduce underlying risks.


Authorization implies that authenticated users will only have access to resources related to their roles. Developers can practice the least privilege policy so that users can operate in a restricted environment. With strict authorization requirements to access resources, the provider can stop users from misusing the API and prevent malicious users from gaining access.


Encryption helps to prevent successful side-channel attacks like the man-in-the-middle (MITM) attack. Even when malicious users can intercept and capture the packets during request and response, it will be hard to decrypt due to the integration of cryptographic protocols like TLS and SSL.

Throttling and Quotas

APIs are an easy target for brute force attacks and DDOS. However, with the activation of quotas and throttling, you can set a rate limit to prevent multiple login attempts and rapid influx of traffic at a time.

API Testing

API testing can create scenarios that will let you see the vulnerabilities in your software and how it will react if a malicious request happens. API testing tools like OWASP ZAP and Test Studio can conduct scans to spot bugs. They can also suggest fixes to security bugs attackers could exploit in the future.

API Logs

An API log will help you document all the activities within your API surface. You can monitor users behavior and see who is abusing the API. In cases where your API is breached, you can have a clear map of how the attacker gained access and patch the loopholes by monitoring the log.

OWASP Top 10

The OWASP top 10 list contains the security vulnerabilities you can have on a web application. Understanding these vulnerabilities and their impact will help to implement hardening policies against threats on your application software.

Strong API Gateway

A good API gateway will help spot vulnerabilities in your network that you might not have found. It’ll also monitor and control your traffic to reduce the chances of a security incident.

Strict Confidentiality

You can erase all sensitive information like passwords or keys from the APIs before making them public. Failure to do this will give hackers the easiest path to breaching your network and wreaking havoc.

Data Validation

This assessment involves screening a request to know if it meets the requirement for the data type it claims to be. You can use schema validation to ensure that every data sent is validated to prevent attacks like SQL injection and XML bombing. The schema will drop all requests that contain extra-sized data.

Consider Starting with Security

Many APIs are vulnerable today because the developers were negligent about security at the early stages. The recommendation is to consider protection during the foundation of your API development cycle. It will help you spot errors and patch countless bugs earlier before exposing your API to the world.

Concluding Thoughts

When it comes to API security, your organization is only as protected as your weakest link. So, it is critical that every layer of your architecture is protected. If you implement these 11 best practices when building your APIs, you’ll be well on your way to having them considered secure.

Test Studio can help you with automated API testing and increase your functional testing efforts regardless of testing seniority or expertise. Book your demo here.

About the Author

John Iwuozor

John Iwuozor is a freelance writer for cybersecurity and B2B SaaS brands. He has written for a host of top brands, the likes of ForbesAdvisor, Technologyadvice and Tripwire, among others. Hes an avid chess player and loves exploring new domains.


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