HTTP API Security Best Practices

In recent years, the importance of web APIs has grown significantly, becoming an essential part of almost all modern applications. APIs are necessary for facilitating the exchange of data and enabling applications to integrate with each other, from a small web application to a huge SaaS service providing a public API. However, with the increase in usage, the need for security has also become paramount.

Threats that Web API faces

There are few security threats that can be faced by any web APIs, making it essential to implement appropriate measures:

• Unauthorized access is the most common API security threat, where hackers exploit the fact that some methods are not adequately secured, obtaining access to other user's private data, execute administrative actions, or disrupt the system's functionality. This often happens when security is not an inherent part of the software development process, or when new endpoints are developed without adequate security measures in mind.

• Distributed Denial of Service (DDoS) is another significant security threat to APIs. Attackers can use multiple machines or bots to send a large volume of requests to the API server simultaneously, causing the server to become overwhelmed and unable to respond to legitimate requests. This can result in system downtime, loss of revenue, and damage to the API provider's reputation

• Another serious security threat are Man-in-the-Middle (MITM) attacks, where an attacker can intercept the communication between the API and the client, modify the contents of exchanged messages, or steal sensitive information. This can happen if the communication channel between the API and the client is not secured properly, making it easy for attackers to eavesdrop on the traffic.

• API injection is yet another security threat, where hackers inject malicious code or data into the API, exploiting vulnerabilities in the application code or the server infrastructure. This can lead to serious security incidents, such as data breaches, system crashes, or unauthorized access to sensitive information.

Best practices for API Security

It is essential to make API security a priority and implement the best practices that fit your application's requirements and risk profile.

1. Prepare yourself a checklist of all the relevant checks that are necessary for the security of API service you are developing. Below, we have provided a list of things that are essential for most APIs, but there may be additional checks that are needed depending on the specific requirements of your service.

☑ Use TLS: Transport Layer Security (TLS) is a must-have for API security. By using HTTPS, communication between the API and the client is encrypted, which ensures the integrity and confidentiality of the data exchanged, and provides protection against Man-in-the-Middle attacks.

☑ Implement authentication: APIs should require authentication to ensure that only identified users can use the service. This can be achieved by using methods such as API keys, tokens, or OAuth. Even when providing a public service, it's essential to ensure some basic level of authentication.

☑ Limit access to a minimum: Always think about limiting access to only the resources that the user needs to perform their job. This reduces the risk of unauthorized access and can be achieved by implementing role-based access control.

☑ Use REST context words and media types: Using HTTP context words such as GET, POST, PUT, and DELETE will provide an excellent starting point for establishing authorization rules. Additionally, the use of media types will add security from API injection by limiting allowable media types only to those expected by the application.

☑ Validate parameters: Always validate and sanitize the parameters passed to the API to ensure that only the data in the expected format will be allowed. This serves multiple purposes: providing instant information to the client that the data they provided is wrong, and reducing the API's exposure to injection attacks.

☑ Limit throughput: Limit the number of requests that can be made to the API by a user within a given time. This reduces the load on your system, protects it from DDoS attacks, and guarantees that every accepted request will be served on time.

☑ Use pagination and caching: Use pagination to limit the amount of data returned by the API to avoid overloading the system. Caching serves a similar purpose, giving an opportunity to reuse previous responses if nothing has changed in the system.

☑ Separate administration API’s: Create a separate API for administration tasks that require additional authorization. This prevents accidental data breaches that can occur if a method without proper authorization is released to the public.

2. Think of is estabilishing Code Review process. Double checking developed code will create additional countermeasure against introducing accidental security vulnreabilities in code.

3. Add package scanning to your build process. Even if your code is developed securedly, you are still exposed to external threats by vulnerabilities and malicious code in external libraries. This is biggest challange in case of JavaScript library repositories like NPM.

4. Always note when  deciding to avert from some points in the checklist. There are many cases why some of the points are ommited, but tracking a decisions will help you to come back to the topic later.

5. Never cease to re-evaluate and update your security measures as new threats emerge and your application evolves.

We take API security very seriously at Craftspire, and we understand how important it is to protect your data and your customers' data. Our team of experts has extensive experience in secure API development, and we can help you ensure that your API is secure from all potential threats. Contact us to learn more about our services and how we can assist you in securing your API.