API Security - Best Practices

It’s nearly impossible to do anything online these days without interacting with an API. As a result, APIs are increasingly being targeted by cyberattacks, and they have become a significant part of the application attack surface. So API security is very important for organizations to secure their data.

Introduction

API is an abbreviation for Application Programming Interface. APIs are mechanisms that allow two software components to communicate with one another by defining and enforcing a set of rules and protocols. Client and server are commonly used to describe API architecture. The application that sends the request is known as the client, and the application that sends the response is known as the server.

APIs can function in four ways, depending on when and why they were created.

SOAP APIs – These APIs make use of the Simple Object Access Protocol. XML is used by both the client and the server to exchange messages. This is a less flexible API that was once more popular.
RPC APIs – These APIs are referred to as Remote Procedure Calls. The client performs a function (or procedure) on the server, and the server returns the result to the client.
Websocket APIs – Another modern web API development that uses JSON objects to pass data is WebSocket API. A WebSocket API allows client apps and the server to communicate in both directions. Callback messages can be sent by the server to connected clients, making it more efficient than REST API.
REST APIs – are the most popular and versatile APIs available on the web today. As data, the client sends requests to the server. This client input is used by the server to initiate internal functions and returns output data to the client. Let’s take a closer look at REST APIs now.

The Risk

The significant increase in usage is due to the critical role that APIs – and web applications in general – play in digital transformation. APIs have aided in the migration from monolithic applications to microservices. They’ve made it possible for businesses to provide user-friendly API-based services for B2B use cases such as automation and integration. They’re also essential to modern web applications, which aren’t just HTML with links anymore, but rather rich user interfaces built as single-page apps with REST API backends. Almost every modern application makes use of – or is made up of – an API.

Why is API security important?

APIs are a lucrative target for hackers because they allow them to gain access to otherwise secure systems and exploit vulnerabilities. APIs are not only prone to the same vulnerabilities as web applications, such as broken access controls, injections, security misconfigurations, and vulnerabilities inherited from other dependent code libraries, but they are also more vulnerable to resource consumption and rate limiting issues due to their automated nature.

Because of a lack of market knowledge, legacy issues from early APIs are frequently carried forward. For example, not all APIs will be protected by an API gateway, with older APIs sitting in the background with little or no protection simply because they are not known about. Due to a lack of standard process and bad practice, many unused APIs will not have been decommissioned, as newer APIs are produced and replaced as a product evolves. As a result, legacy APIs may be vulnerable to attacks.

How to Protect the API

The first step in securing your APIs is to audit your environment and/or applications to determine what APIs you have and which ones you use. Then, in order to validate that each API is working as expected, you must first understand its purpose. You must also understand the API’s expected behavior in order to detect threats more easily by capturing abnormal activity. Once you understand the API’s functionality and expected behavior, you will be able to manage and test your API more effectively and efficiently.

API management is a critical component of API security. APIs require not only the same controls as web apps but also additional controls unique to the API’s function. API documentation and version control are critical because one product may have hundreds or thousands of APIs.

Poor management can result in issues with legacy and defunct APIs, as only a small percentage of APIs pass through an API gateway. Meanwhile, older APIs that haven’t been decommissioned or that teams aren’t aware of can sit in the background unprotected. The likelihood of known vulnerabilities in older APIs is also significantly higher, adding to the risk profile.

The same legacy issues can cause coverage gaps, and calls made outside of an API gateway may leave a blind spot for intra-API calls. Publishing and clearly defining your API will help users understand it better and connect in the most appropriate and effective way. A key management technique is to ensure that your API is properly monitored.

Continuous performance checks will allow you to determine whether the API is under stress as a result of being overloaded. It can also provide an indication of traffic volumes to monitor usage, potentially detect malicious activity (via audit logs), and determine whether your operation needs to be scaled up.

Finally, having an attack response plan in place is a critical control in API security, allowing for a quick but controlled response to potential threats.

The following are some simple but effective steps you can take to secure your API and reduce the risk of such exposures:

Authentication: Do you have a way of knowing who is calling your API?
Authorization: Should the person calling have access to this information?
Encryption: Is your network traffic encrypted?
Traffic management: Have you set rate limits or thresholds to prevent a customer from pulling too much data or running scripts that clog an API?
Audit logging: Effective logging allows you to understand what normal traffic looks like and detect abnormal activity.

How to examine your API

API testing continues to evolve to accommodate the rise in volume and complexity. Manual API security testing is possible with traditional testing tools, and fully automated API security testing is partially supported by the majority of major DAST solutions. However, many open-source tools have been developed for guided API security testing. In conjunction with proper API management, API testing will increase API security.

API testing is most effective when you have a complete risk profile of your business, i.e. you are aware of all of your APIs (including legacy or defunct APIs) to ensure that there are no exposed or exploitable blind spots. API security is improved by identifying vulnerabilities in API frameworks, your network, configuration, and policy.

By anticipating threats by understanding expected behavior and implementing sufficient testing, proactive coverage, enhanced protection, and threat identification can be achieved.

Lastly, you must continuously test your endpoint to guarantee that protection is always maintained and optimal security is in place. The ability to identify and prevent security risks before they occur is pre-emptive security.