API Security Best Practices (complete with a checklist)

Cybersecurity has come a long way in the last couple of years, and with the advancement of security, there is also an advancement of those creating more complex and sometimes more discernibly simple attacks such as an API security breach.

There are many unique challenges associated with API security that CISOs and organisations have to face. Unfortunately due to their nature, they can be easily hacked and give cybercriminals access to sensitive financial, medical and personal data.

In this article, we are going to take a closer look at what API security is, the importance of API security, and finally some best practices (with a checklist).

What is API Security?

API Security refers to methods that prevent malicious attacks on application program interfaces (API).

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 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.

With the advent of social media in the early 1990s and the explosion of the internet on mobile devices, it has become a go-to mechanism for both developers and end users to get sites and systems interacting with each other through APIs. However, this has brought about many new challenges and headaches for CISOs around the world.

The Importance of API Security

As mentioned in the introduction, cybersecurity has only had to get better thanks to the emergence of new technologies and cybercriminals becoming faster and more advanced in their attacks.

One particular area of their interest is in API security, as API interfaces provide a high level of exposure, and potentially provide access to large volumes of sensitive and valuable information.

In 2020 alone, there were over 15 billion incidents involving compromised credentials, which led to a significant number of major data breaches. Some examples of API hacks and security issues include:

  • Injection attacks such as SQL Injection, NoSQL, LDAP injections, Cross-Site Scripting and XXE (XML Entity), caused by a lack of strict input validation, where untrusted data is transferred into the API.
  • Data exposure issues are a common REST API security vulnerability.
  • Man-in-the-middle attacks (MiTM), where an attacker is positioned suitably between two parties to intercept or change communications.
  • Insufficient logging and control means security teams can miss relevant events that must be logged to help incident response teams or for audit trail purposes.

API Security Best Practices

Whilst APIs are enormously beneficial, they present significant security challenges. Thanks to their benefits, both by the developers and the end users; APIs can still be enjoyed with minimal risk to data by adhering to some simple best practices.

The following is a basic checklist that you can begin to implement into your API security protocols. As with any cybersecurity issue, it is best to seek advice from experts in the area such as BlueFort.

How can you protect your data from API security issues?

Use Encryption

One of the best ways to protect your API security is to use the latest TLS versions to block the usage of the weakest cipher suites.

Organisations using APIs which routinely exchange sensitive data (such as login credentials, credit card, social security, banking information, health information), TLS encryption should be considered essential.

Use Strong Authentication and Authorisation

Poor authentication or non-existent authorisation are major issues with many publicly available APIs. They provide an entry point to an organisation’s databases, it’s critical that the organisation strictly controls access to them.

You can create the right security protocols to protect your organisation. Authentication methods include:

  • HTTP basic authentication where a user needs to provide user ID and password.
  • API key where a user needs to provide a unique identifier configured for each API and known to API Gateway.
  • A token that is generated by an Identity Provider (IdP) server. OAuth 2 is the most popular protocol that supports this method.

When feasible, use solutions based on solid, proven authentication and authorisation mechanisms such as OAuth2.0 and OpenID Connect.

Prioritise API Security

One of the key battles with API security is that it is sometimes considered when it is too late. Another issue is that API security is someone else’s issue. Making API security a priority is a business necessity, after all, organisations need to recognise they have a lot to lose with unsecured APIs.
A key element to this is to allocate appropriate investment. With the right investment, you can protect your API security with better tools.

Be Aware of all APIs

Whether an organisation has one or hundreds of publicly available APIs, building an inventory of all the APIs so that they can be secured and managed using perimeter scans, along with insight from developers, to create an inventory of all APIs is the best place to begin.

Practice the Principle of Least Privilege

It is a security principle that effectively holds that the subjects/entities (users, processes, programs, systems, devices) are only ever granted the minimum necessary access rights to complete a required function. This is something that applies more broadly to all IT systems, and it should be applied equally to APIs.

Don’t Expose More than is Necessary

One of the biggest issues with APIs is that they are designed to allow for the exchange of data. In short, APIs can reveal more information than necessary.

With API security you should ensure that APIs only return as much information as is necessary to fulfil their function i.e. form fill outs should only exchange the data on the form and nothing else on a system.

In addition, enforce data access controls at the API level, monitor data, and obfuscate if the response contains confidential data.

Always Validate Input

All input data must be validated, and anything that is too big or doesn’t comply with required checks must be rejected. Ensure injection exploits are prevented.

Ensure all OWASP Vulnerabilities are Secured

Avoid WASPS. The OWASP (Open Web Application Security Project) Top 10 is a list of the ten worst vulnerabilities. It should be ensured that systems have been secured for these vulnerabilities.

Implement an API Management Solution

Good API management solution will help make sense of API data, and establish secure API practices.

Get Help from Security Experts

The world of cybersecurity is enormously challenging and continuously evolving with new threats appearing daily. Partnering with experienced cybersecurity experts who know exactly what’s needed to secure enterprise level API based systems, is often the best API security solution.

BlueFort’s security solutions are ideally positioned to help organisations be prepared for API attacks and more.

API Security Checklist

There is a simple checklist that can be used to audit/assess current API security practices:

  • Is API security prioritised in your organisation?
  • Do you have an up to date, accurate inventory of all APIs used by your organisation?
  • Is API encryption used appropriately?
  • Are strong authentication and authorisation mechanisms used for all API interactions?
  • Are the principles of ‘least privilege’ being used to provide only the minimum levels of access required by APIs?
  • Are any APIs exposing more than is needed?
  • Are all API inputs rigorously validated?
  • Are all OWASP vulnerabilities secured?
  • Have you implemented an API management solution?
  • Have you consulted with cybersecurity experts?


API Security refers to methods that prevent malicious attacks on application program interfaces (API). 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.

Because of their nature, APIs can pose massive security risks. There are however plenty of security solutions that can be implemented to better protect organisations from API security attacks.

If you are looking to get a better understanding of where your organisation’s cyber weaknesses lie, BlueFort’s Evolve IT Services can help you to get a much better understanding of these threats and also provide you with the solutions to protect your organisation in the long term.

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

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