API Security Testing – Everything You Need to Know

It’s incredible to think that APIs have been with us since the year 2000 but only in the last decade has their use exploded.

In fact, if you were to look at some basic statistics, nearly 61% of developers reported using more APIs in 2020 than in previous years, and that number would rise to 71% in the coming years. 

However, thanks to what they are and how they transfer vast amounts of data, APIs are posing a wide range of security risks and with that, there are various challenges associated with API security testing that need to be better understood and discussed. 

In this article, we are going to further explore the topic of API security testing, why it is important, the common types of API security testing, best practices, and discuss how API security testing works. 

What is API Security Testing?

APIs are Application Program Interfaces and they connect services to transfer data. They are extremely useful as they allow two different programs to interact with each other i.e. Google with Booking.com.

APIs help developers by simplifying the coding process and granting them access to a wealth of data and resources they would not otherwise be able to access.

Thanks to their ability to talk to different systems, developers have become very accustomed to implementing them across sites, and using them as part of a wider connectivity strategy. However, as the use of APIs to connect systems and data increases, their value and associated security requirements also rise. 

In order to ensure that API security is maximised, API security testing is required. API security testing is the process of checking for vulnerabilities in all APIs and ensuring compliance with the required standards at all times.

Why is API Security Testing Important?

Because they are at the heart of so many applications, making sure that APIs are conformant to published specifications and resilient to bad and potentially malicious input is critical to an organisation’s overall security. 

They are being widely used by developers across multiple platforms and sites, which means that the traditional methods of searching for security breaches are no longer suitable and in return, result in compromised security for the organisation.

The possible consequences of API security breaches include:

• Leakage of customer/sensitive data.
• Hacking of web properties.
  • The short answer to if an API can be hacked is, yes, it can be hacked. Like all web-based applications, they have different levels of visibility which can result in security breaches.
• Negative impact on users and revenue.
• Possible lawsuits if negligence has occurred.

Naturally, if you were to begin API testing, there has to be some form of associated benefit. At the most basic level, API security testing helps identify and prevent vulnerabilities and their associated potential organisational risk. Other associated benefits include;  

• It helps identify and prevent vulnerabilities and reduce risk.
• API security testing can help identify where an API diverges from published API specifications.
• Proactively identify and detect software security issues in APIs before they are deployed to production environments.
• Security compliance and reporting analytics provide real-time awareness of threats associated with APIs.

Common Types of API Security Testing

In response to the ever-increasing demands of API testing, there are three main types of tests you can perform. These tests include:

• Security Testing
  • Security testing validates whether the basic security requirements have been met.
  • This testing stage of the process comes first, and will help prevent the major vulnerabilities.
• Penetration Testing
  • External aspects of the API are attacked in a deliberate fashion in a controlled environment. This can be done using automated tools.
• Fuzz Testing
  • Fuzz testing pushes an API to its limits.
  • This can involve sending vast request volumes at the API and attempting to vary the data in as many creative ways as possible to reveal vulnerabilities.

There are also different types of classifications of API security tests, these include; 

• Dynamic API Security Tests
  • The best form of API security testing is running active (dynamic) tests against your API endpoints. This active testing is technically a form of dynamic application security testing (DAST).
• Static API Security Tests
  • This form of testing looks for patterns in the code that represent potential security concerns.
• Software composition analysis
  • Software Composition Analysis (SCA) tools look at the dependency tree of an application and match this against a database of known vulnerabilities.
    How API Security Testing Works

When it comes to security testing it’s important to remember that basic security requirements have to be met.

The idea behind API scanning is to craft inputs into coax bugs and undefined behaviour out of an API – essentially mimicking the behaviour of a hacker. 

You can carry out API security testing in a variety of ways, including;

• Determine Security Requirements.
  • Define what constitutes a pass or failure.
• Establish the testing environment.
  • Can require specific environments for larger applications.
  • While smaller applications a standard staging environment would work.
• Verify the API is setup / configured as required.
• Clarify all parameters that will be used in test cases.
  • Identify edge cases that need to be examined.
• Develop test cases.
• Execute tests.
• Assess results.

API Security Testing Best Practices

Of course, in order to ensure that API security testing is working as it should, there are a variety of testing best practices which can be implemented in the testing environment, this includes; 

• Be highly aware of the risks of APIs.
• Understand that APIs are difficult to use – so mistakes can be made.
• Add on software must be rigorously monitored.
• Be aware of standards issues.
• Focus on front end authorisation and authentication.
• Remember to implement backend checks (preventing data from being stolen / moved without authorisation).
• Consider the use of API security tools and gateways.
• Provide adequate budget / investment to cover API security testing.

The Next Steps 

APIs have become a go-to for developers and organisations who are looking to make their systems more easy to communicate with other systems, and in return help end users find a simple way to navigate between systems.

However, with this kind of development it has opened the doors to hackers being able to take vast amounts of data from organisations and users. 

API security testing allows CISOs and organisations to get a grip on where there are potential weaknesses and in return, mitigate any potential future issues. 

If you are looking to get a better understanding of where your organisation’s cyber weaknesses lie, BlueFort’s Evolve IT Services can not only help you get a much better understanding of these threats but also provide you with the solutions to protect your organisation in the long term.

Call 01252 917000, email enquiries@bluefort.com or get in touch with us via our contact form.