API (application programming interface) security audits are crucial because APIs enable seamless communication and data exchange between software systems. These audits are necessary for organizations to identify risks, assess them, and strengthen defenses against breaches and attacks.

In this blog, we'll cover the basics of API security audits and highlight some common API security threats. We’ll also discuss the advantages of conducting API security audits and provide a guide on conducting API security reviews and the best practices for API security audits.

Let's dive in!

What is an API Security Audit?

An API security audit is a review process that thoroughly evaluates APIs' security levels and helps strengthen them with appropriate security measures if needed.

These security measures ensure data integrity and confidentiality and safeguard APIs from the following threats:

• Unauthorized access

• Data breaches

• Abuse

• Fraud

Security audits conduct over 200 checks on the API, covering its structure, semantics, security, and input and output data definitions. The Security Audit evaluates the API in three areas:

1. OpenAPI Format: Assess whether the API is a valid and well-formed OpenAPI file that adheres to best practices and the OpenAPI Specification.

2. Security: Examine the quality of the security definitions in the API, including the presence of secure authentication and authorization methods.

3. Data Validation: Review the quality of the API's data definitions, including the definition of acceptable input data and the strength of the defined schemas for the API and its parameters.

Let's review the threats that call for security audits in greater detail!

What are Some API Security Threats?

Here are some of the notable examples of API security threats:

1. Data Breaches

Attackers exploit API vulnerabilities to access sensitive data, such as user credentials or financial information, enabling identity theft or fraud. This can result in severe financial and reputational damage for organizations.

An example of the consequences of weak API security is the LinkedIn API Breach of 2021. In this incident, attackers exploited a public API without authentication, which compromised data associated with 92% of its users.

The hackers then sold the data on a forum. Such cases highlight the risks of insecure APIs, the loss of sensitive information, and the threats of data breaches.

2. Denial of Service (DoS) Attacks

In DoS attacks, attackers flood APIs with excessive requests, crashing them and denying legitimate users access. Such disruptions can lead to significant business losses and user dissatisfaction.

3. Malicious Payloads

Attackers insert harmful code into API requests to exploit vulnerabilities, potentially leading to unauthorized access or data theft. This can compromise the integrity of the system and expose sensitive information.

4. Man-in-the-middle (MITM) Attacks

In cases of MITM, attackers intercept and alter communication between clients and APIs. This leads to data theft or manipulation. Such attacks can undermine the trustworthiness of the communication channel.

5. Unauthorized Access

Weak authentication or access controls allow attackers to gain entry into APIs, risking the exposure of sensitive data and system misuse. Implementing strong authentication mechanisms and regular access control reviews can mitigate this risk.

Advantages of Conducting API Security Audits

Here are the key advantages of conducting API Security Audits periodically:

1. Mitigating and Reducing Risks

By discovering vulnerabilities and other faults, organizations can proactively address them, thus reducing the likelihood of encountering unwanted data breaches, cyber-attacks, and other security threats.

2. Savings Costs

Regular security audits are always a better cost-effective strategy than dealing with the aftermath of a data breach or cyber attack. The expenses associated with a security breach, such as legal fees, reputational damage, and loss of customer trust, can far exceed the investment in preventive measures such as security reviews.

3. Safeguarding Data Confidentiality

APIs often handle sensitive data, such as personal information, financial transactions, or intellectual property. Conducting security audits ensures that this data remains protected from unauthorized access or exposure and safeguards its privacy and confidentiality.

4. Ensuring the Integrity of Data

APIs enable the exchange and modification of data, making it crucial to maintain data integrity. Hence, security audits help organizations detect and prevent unauthorized data alteration, including tampering and spoofing attacks. They also ensure the accuracy and reliability of data exchanges.

How to Conduct API Security Audits?

Below is the step-by-step process on how to conduct API security audits effectively:

Step 1: API Endpoint Identification

In the initial step, organizations should identify and categorize API endpoints based on their functionalities, susceptibilities, and importance. This involves detailed mapping of requests, responses, and other relevant attributes to establish comprehensive documentation.

Step 2: Authentication and Authorization Verification

This phase emphasizes verifying that organizations restrict access to authorized users and ensure they have permissions for specific actions. Application security engineers determine this through rigorous tests on access controls to prevent unauthorized access.

Step 3: Input Validation and Data Integrity Maintenance

Ensuring API security necessitates robust input validation tools to monitor and maintain data accuracy and integrity. This includes validating the input values within the anticipated data formats, lengths, types, and ranges. It also effectively prevents injection attacks like SQL injection or XSS.

Additionally, data integrity control measures such as message authentication codes (MACs) or digital signatures safeguard against data tampering during transmission.

Step 4: Effective Error and Exception Management

In API development, it is important to handle errors and exceptions well. Security engineers must provide clients with error messages that contain the right details while keeping sensitive information safe.

Good exception management quickly finds and fixes exceptions to stop API crashes or accidental leaks of sensitive data.

Step 5: Implementation of Rate Limiting and Throttling

Employing rate limiting and throttling strategies reduces client requests to an API within stipulated intervals. This helps to shield the API from data abuse and ensures availability and responsiveness to other legitimate users.

Throttling is like rate limiting, but it dynamically adjusts request rates based on traffic and server load conditions.

Step 6: Automated API Abuse and Security Testing

API abuse testing entails identifying and fixing security vulnerabilities originating from API usage. This includes preventing authentication breaches, SQL injections, and unauthorized requests that could cause Denial-of-Service (DoS) attacks.

Hence, leveraging security testing automation tools and scripts streamlines the testing process for security engineers and helps them efficiently uncover potential security loopholes.

API Security Audits Best Practices

It's critical to adhere to industry-standard best practices, keep up with emerging threats, and constantly monitor and retest to maintain robust security. Here are some of the best practices to follow:

1. Following Industry Standards

Adhering to industry standards and regulations is essential to ensuring strong API security. These standards simplify the implementation of appropriate security measures and successfully reduce periodic threats.

This API security best practice is crucial for organizations and application security engineers as it can help them lower the risk of possible data breaches and match their security measures.

2. Staying Up-to-Date with Evolving Threats and Security Practices

Keeping up with evolving threats is essential for API security. Threats constantly evolve, and novel methods for attackers to exploit vulnerabilities arise regularly.

So, if organizations and security engineers learn about these risks, they can spot weak points early and act before they're taken advantage of. This means staying ahead of attackers by being part of the security community, going to conferences, and using sources for threat information.

3. Implementing Continuous Monitoring and Retesting

Continuous monitoring and regular retesting are key to maintaining strong security over time. Conducting a security audit once is enough—it's an ongoing process.

APIs and their threats constantly evolve, so application security engineers must continuously monitor to detect and respond to security issues as they arise. Regularly retesting identifies and resolves any new vulnerabilities introduced by system updates or changes in the threat zone promptly.

Final Thoughts

API security audits play a vital role in identifying vulnerabilities and strengthening defenses against common threats like data breaches and DoS attacks. By systematically assessing API security, organizations can mitigate risks, protect sensitive data, and maintain system integrity.

Regular audits not only save organizations costs associated with breaches but also ensure that they comply with industry standards. Organizations should streamline the entire process by leveraging an API security platform with robust capabilities.

Akto is a Proactive API security platform that is one of the best tools in the industry for security teams and organizations. Its user-friendly, consolidated platform makes reviewing API security hassle-free. Akto also comes with built-in tests that can effortlessly help organizations detect data vulnerabilities in your system. It also lets you create custom tests if needed.

To explore Akto’s comprehensive capabilities, book a demo today!