API Security Best Practices: An In-Depth Overview

Application Programming Interface (API) is a set of protocols and tools that allow software applications to communicate and interact with each other. By using API, developers can enrich their solutions with the functionality of other services, libraries, or platforms rather than building everything from scratch.

Since APIs often transmit sensitive and confidential data, maintaining strong API security measures is of utmost importance.

Continue reading to find out about the core API security risks and business consequences associated with them. We’ll also highlight API security best practices and tools so that you’re all set to protect your APIs from intruders.

What are the business consequences of compromised APIs?

In the Q1 2023 State of API Security report, 31% of respondents indicated sensitive data exposure, while 17% experienced data breaches due to gaps in API security.

API incidents often lead to tangible business setbacks, including:

• Financial losses — security breaches require investigation and mitigation, which may lead to heavy expenses.
• Reputational damage — API security violations can severely impact a company’s reputation, resulting in the loss of trust from customers, partners, and stakeholders and even lawsuits from affected parties.
• Operational disruption — compromised APIs can lead to service malfunctions or downtime, affecting customer experience and leading to lost revenue.
• Intellectual property theft — hacked APIs may expose proprietary code or algorithms, allowing competitors to gain access to the company’s sensitive intellectual property.

What are the top 5 common API security risks and how to prevent them?

There’s a range of risks associated with API security. According to the Open Worldwide Application Security Project (OWASP), some of the most common ones are broken authentication, broken object level authorization, denial of service (DoS) attacks, broken function level authorization, and unsafe consumption of API.

Let’s examine each of these risks in greater detail.

1. Broken authentication

Broken authentication API security risk happens due to the improper implementation of authentication mechanisms, such as weak credentials, lack of multi-factor authentication and encryption, predictable session IDs, etc.

By exploiting this vulnerability, attackers gain unauthorized access to user accounts, sensitive data, and core system functionalities. This can lead to unauthorized data exposure, loss of confidentiality, account takeover, and various other security breaches.

Preventive actions:

• Implement strong authentication mechanisms, including multi-factor authentication (MFA) and CAPTCHA
• Enforce password complexity requirements to prevent the use of common or easily guessable passwords
• Ensure secure session management with defined session timeouts and unpredictable session IDs
• Watch out for compromised API credentials on the dark web and take action accordingly

2. Broken object level authorization

The broken object-level authorization (BOLA) vulnerability occurs when a user gains access to other users’ data due to incorrect access control measures on data objects. This vulnerability often arises from APIs that implement excessively permissive access controls or inadequately protect API resources.

Unauthorized access to other users’ objects leads to data exposure, loss, or even manipulation. In the worst-case scenarios, unauthorized object access might even result in a complete account takeover.

Preventive actions:

• Conduct thorough authorization checks at both the API gateway and the backend services
• Employ strict role-based access control principles to define user roles and their corresponding access rights
• Implement multi-factor authentication where possible
• Leverage random universally unique identifiers
• Avoid using direct references, such as object IDs or URLs, since attackers can manipulate them. Use indirect references or tokens instead

3. Denial of service (DoS) attack

Fraudsters can initiate multiple concurrent requests to API to consume excessive amounts of system resources, such as memory or network bandwidth. This is called a denial of service attack. The consequences of API DoS attacks include system slowdown or crash, causing disruptions for legitimate users.

To execute such attacks, fraudsters might exploit vulnerabilities in the API’s input validation, authentication mechanisms, or rate-limiting controls. Attackers often employ automated tools and bots to efficiently distribute malicious requests, making detection and mitigation more challenging.

Preventive actions:

• Enforce rate limiting on API requests
• Set up monitoring systems to track resource usage patterns and detect anomalies
• Use cloud infrastructure that can automatically scale resources in response to sudden spikes in traffic
• Integrate Web Application Firewalls (WAFs) to identify and block suspicious patterns of traffic

4. Broken function level authorization

A broken function-level authorization API vulnerability refers to a situation when a regular user can perform actions that should be only available to admins.

This happens when role assignments are not managed properly and may allow malicious actors to gain unauthorized control over critical functions, potentially compromising data, system integrity, and security.

Preventive actions:

• Enforce role-based access control (RBAC) to properly assign roles and permissions to users based on their responsibilities
• Assign users with the minimum permissions required to perform their tasks
• Regularly review and update access control policies
• Utilize an API gateway that can centralize and manage authorization logic for all API endpoints

5. Unsafe consumption of API

If an application doesn’t properly check, filter, and clean the data it receives from external APIs, it can lead to unsafe consumption of API. This leads to security threats such as data leaks or injection attacks. During these attacks, hackers insert harmful code into input fields to manipulate the API system and execute malicious commands.

As a result, the integrity and confidentiality of both the application and the data it interacts with gets compromised.

Preventive actions:

• Thoroughly validate and sanitize input data to prevent injection attacks and ensure data integrity
• Ensure all API interactions happen over a secure communication channel
• Keep an allowlist of trusted locations integrated APIs may redirect you to

7 API security best practices you should follow

In addition to risk-specific API security practices mentioned above, there are also general safety rules you should follow to protect your API:

1. Identify vulnerabilities — conduct a regular evaluation of your API’s code and configuration to identify areas that might be susceptible to vulnerabilities. This will allow you to work out an effective risk management strategy.

2. Conduct regular API security testing — maintain frequent security and quality assessments, including penetration testing and code reviews, to timely identify and address vulnerabilities.

3. Keep API updated — regularly upgrade your API security protocols and mechanisms to stay protected against known vulnerabilities.

4. Handle errors properly — implement informative, yet non-disclosing error messages to prevent information leakage.

5. Leverage a robust API gateway — use an API gateway for centralized API management and security controls.

6. Maintain clear API documentation — provide accurate documentation for API consumers, including security best practices.

7. Foster a culture of security awareness — deliver ongoing training to your development and operations teams so that they know all the necessary security procedures and can implement them efficiently.

3 best API security tools

Some tools can assist you in maintaining strong API security. Here is the overview of the top three solutions selected by our experts:

Fiddler

Fiddler is an application that enables developers, security professionals, and testers to monitor, intercept, and inspect HTTP and HTTPS traffic between a client and a server.

The solution can capture API calls and examine requests and responses to help you identify potential security vulnerabilities, such as weak passwords or the exposure of sensitive data.

Using Fiddler, you can also make real-time adjustments to requests and responses during testing to explore different scenarios such as input validation, injection attacks, and parameter tampering. Plus, the application can analyze response times, load times, and latency of API requests, allowing you to identify bottlenecks.

Fiddler is compatible with Windows, macOS, and Linux operating systems and can also be used on mobile devices. Moreover, the solution seamlessly works with an extensive array of frameworks, including Java, JavaScript, Python, Ruby, SOAP, REST, and GraphQL.

Wallarm API Security Platform

Wallarm API Security Platform can identify and mitigate vulnerabilities, ensure the integrity of communications, and protect API against attacks.

To detect anomalies that might indicate an attack or unauthorized access, Wallarm uses behavioral profiling and compares current activity with normal API traffic patterns.

The solution can also perform comprehensive security testing to identify technical vulnerabilities, business logic flaws, and security misconfigurations. To ensure clear reporting and comprehension, the platform provides detailed reports and insights.

The Wallarm API Security Platform is compatible with different frameworks, such as NET, Java, Python, Node.js, Ruby, and even cloud frameworks: AWS Lambda, Azure Functions, and Google Cloud Functions.

OWASP ZAP

OWASP ZAP (Zed Attack Proxy) is an open-source tool specifically designed for enhancing the security of APIs and web applications.

OWASP ZAP can automatically scan APIs to identify a wide range of vulnerabilities, including injection attacks, broken authentication, cross-site scripting (XSS), and more. For optimal effectiveness, the solution enables manual intervention during scans, giving security professionals the ability to engage with the API and evaluate vulnerabilities in real time.

OWASP ZAP also allows developers to test how their APIs handle different user roles and access permissions by trying out various authentication methods.

Since it is an open-source project, OWASP ZAP benefits from an active community with members continuously enhancing and updating its capabilities.

OWASP ZAP is compatible with a diverse array of frameworks, including but not limited to Java, Python, Ruby, PHP, React, and various API technologies such as REST, SOAP, and GraphQL.

Conclusion

API is an incredibly efficient and valuable tool that enables different solutions to work together. However, if API security isn’t properly handled, there’s a significant risk of revealing sensitive business and client information or even losing control over the system.

Our experienced software developers and consultants are ready to guide you through creating and implementing robust API security measures, safeguarding the integrity of your data.

Contact us and let’s make this API tamperproof.