Best Practices for API Security
02 Aug

Best Practices for API Security

Mahipal Nehra

What are the best practices for API Security? To develop and deploy web applications in the iterative yet fast-paced process, developers tend to rely on application programming interfaces (APIs) for communication between different services. At the same time, API gateways manage the APIs between client and backend services.

And as with all content that is accessed through the internet, APIs and API Gateways are also vulnerable to myriad threads if they aren’t secured appropriately. Moreover, without proper authorization and authentication, anyone will be able to access the data of your web application leading to significant data loss and user data privacy violations.

So, in today's blog, we will discuss everything you need to know about API Security and the ways to secure your system from threats on API.

Threats to API Security

Although APIs bring many benefits to web application developments, API attacks have risen considerably for enterprise application data breaches every year. APIs are tools chosen by developers for machine-to-machine or service-to-service, or frontend-to-backend communication. APIs include all the required commands, data, and payloads to create remarkable user experiences.

Read More: Microservices vs API: How They Differ From Each Other?

However, using too many APIs without encryption can lead to potential cyber-attack risks. Simply put, the high inclusive API usage introduces numerous challenges to the system. Some of them are:

  • Unknown attack surface: No knowledge of hidden, third-party, deprecated APIs in the system can leave it vulnerable to cyber-attacks.

  • New exploit opportunities: Lack of software development best practices, improper training, and other errors from developers can also lead to potential risks in the system.

  • Breaches and disruption from automated attacks: Although APIs allow great communication between backend systems, they can also make themself a primary target for business logic abuse and attacks even after applying best code practices. But these challenges are just the scratch to the surface, if we go a little further, significant attacks that APIs can bring to your web application are:

  • API Injections (SQLi and XSS): Injection attacks occur when an attacker inserts malicious commands or code into the source code, especially when the login is expected. While cross-site scripting (XSS) injection attacks when the attacker injects malicious script into the web page code to gain its control, SQL injection attacks allow attackers to gain access to the SQL database.

  • Distributed Denial of Services (DDOS): By increasing the traffic in the system, network, or website than it can handle, DDOS attacks make it unavailable to the users.

  • Man In The Middle (MITM): MITM attacks take advantage of traffic between two given communication systems and mimic each other while acting as a hidden proxy between them. It can occur between the API and the client or between the API and the endpoint.

  • Credential Stuffing: In credential stuffing, hackers use stolen credentials for API authentication to gain access to the system.

How API Gateway & Firewalls Secure APIs?

Now that we know the potential risks a system might have, it’s time to look at what API Gateways and Firewalls are and how they can help in securing APIs.

  • Web application firewalls: Firewalls are designed to address the requirements of PCI section 6.6 and use signatures to identify known vulnerabilities OWASP web app list of threats describes. However, firewalls struggle to detect and block what looks legitimate as well as threat prevention from inventory tracking, visibility, and assessments that are needed for API security.

  • API Gateways: API gateways are designed to aggregate and handle APIs. Gateways provide basic security functions, like IP blocking and rate limiting, and provide access control. API gateways are deployed in the infrastructure of the web application that gains complete risk assessment, visibility, inventory tracking, and apply common security practices to prevent API threats.

Although both firewalls and API gateways can offer basic protection for APIs, they cannot address all the requirements for API security including detection of inherent risks, protection of associated threats, and identifying every API.

Best Practices for API Security

What are The Best Practices for API Security? Some of the best practices to secure API against attacks are as follows:

1. Security Prioritizing

Securing APIs should not be treated as an afterthought or “someone else’s problem”. If the APIs are not secured appropriately, it can cause major loss in the business, hence, treating API security as a priority and implementing security practices as APIs are being developed can be of great help.

2. API Management

Whether a web app has a few or hundreds of APIs that are available to the public, it is a must to keep a tab on each API used for security while managing them. Shockingly, many businesses aren’t aware of the total number of APIs implemented in their web application. So, it becomes a must to conduct scans to discover and record APIs and work with the DevOps team for API management.

3. Strong authentication and authorization

Poor authorization and authentication in the web app where multiple APIs are available for the public can become a major threat to the business. Authentication that is not enforced by APIs or the implemented authentication that is almost non-existent can cause broken authentication. Moreover, as APIs provide an access to the database of the business, it is significant to strictly control its access. To avoid any unauthorized access to the system, developers must add proven authorization and authentication solutions like OpenID Connect or OAuth 2.0.

4. Practice the Principle of Least Privilege

It is a concept to secure APIs that helps in limiting user access and only allows them to strictly access what is needed to fulfill their tasks. Although the principle is subjected to users, programs, devices, systems, and processes, it can also be implemented in APIs.

5. Encrypt traffic using TLS

Often API payloads are not encrypted for the data that are not considered sensitive, but for web applications where APIs exchange sensitive data like social security, credit card, login credentials, banking & health information, TLS must be used to encrypt API.

6. Remove Unnecessary Information

Some APIs show too much information such as data returned through API or the details of the APIs endpoint. It often happens when APIs filter data tasks to the user interface rather than the endpoint. So, it is important to ensure that only necessary information is revealed by the API to complete the provided task. Moreover, data access control, scanning tools, and data monitoring should be incorporated into the process to limit accidental exposure of sensitive or unnecessary information.

7. Validate input

A validator should always be used before passing input from an API to an endpoint.

8. Use rate limiting

Setting a request threshold for the web app can prevent distributed denial of services to the users.


The apps that we use for our day-to-day lives are based on APIs that connect back to resources in the data center, cloud, or both. To ensure API security, businesses prefer to adopt an API-first methodology for development. Developers opt for an API-first approach because it makes the API efficient, powerful, and flexible.

Read More: 7 Best Practices for Testing APIs

Sadly, cyber attackers like APIs as much as developers due to the fast communication they provide, making APIs much more susceptible to vulnerabilities, exploitations, and automated attacks that compromise system security and lead to major data loss.

Read More: API vs Web Services: The Basic Concept, Examples, and Differences

And as stated above, developers need to secure both existing and future APIs by implementing significant security solutions that can complete the API gateways and Firewalls' basic capabilities. For that developers can implement an API security solution that monitors security risks, API runtime visibility, and unusual behaviors in the system.

Read More: API VS Web Services VS Microservices

And if you hire developers who have gained years of expertise and experience from companies like Decipher Zone Technologies, they can help you to achieve the desired security in your system with ease.

Posted by Mahipal Nehra | Posted at 02 Aug, 2022 Web