The application program interface (API) currently serves as one of the vital components of modern software development. It enables seamless interaction between different applications through a structured interface, ensuring smooth data exchange and elevated user experience.
It has become an integral part of the modern IT system and internet, supporting IoT devices, SaaS, and web applications. As the use of API in modern applications is increasing, it is becoming a prime target of cyberattackers and a single vulnerability can cause a complete breach.
Thus, API security has become a primary requirement in SDLC to ensure vulnerabilities are detected and remediated quickly before they are exploited. Today we are going to understand what is API security and explore API security best practices you should follow.
Without, let’s dive right in!
What is API Security?
Application Programming Interface (API) security is an important pillar of modern applications security that protects API from any kind of cyberattacks. From unauthorized access, DoS attacks, and data breaches to MITM attacks, data injection, and various types of security threats, APIs are plagued by different types of attacks.
OWASP defines API security as the strategies and solutions that are involved to identify and mitigate vulnerabilities and security threats associated with APIs. At its core, it employs all the necessary techniques to ensure that only authorized applications or users can access and use the API.
Typical API security involves the process of encryption, authorization, monitoring, rate limiting, input validation, and authentication before it facilitates the exchange of data between two software solutions.
Since APIs are responsible for transferring data between applications, API security is responsible for the confidentiality of the data before it is fed to users, servers, and applications.
Nowadays most applications depend on API for functioning and it leads to additional risk as it allows third-party applications and users to access it. This is the reason, it has become necessary for every organization to employ API security and protect the backend framework of applications.
Importance of API Security
Web applications are becoming an integral part of modern businesses and usage of APIs in applications is increasing day by day. APIs have become the backbone of modern applications, especially cloud-native applications.
Moreover, it acts as a backend framework for most SaaS, web applications, and customer-facing solutions. The number of API users is increasing with time as more organizations enable access to services and data through API.
To put that in perspective, Salt Security customer data indicates the API traffic per customer increased by 168% from 2021 to 2022. Importantly, API is associated with resources, sensitive customer information, and application logic and a breach can expose all of them.
As a result, API serves as a lucrative attack vector for most attackers. If they are able to access a vulnerable API, it can give complete access to manipulate an application, disrupt business operations, or steal sensitive information.
Most of the web services providers involve stringent security and incident response measures including MFA to prevent attacks on API. From SQL injection, and cross-site scripting to data breaches, API security plays a vital role in preventing a varied type of attacks and securing the performance of APIs along with the application.
Common API Security Threats
API security plays a crucial role in safeguarding APIs utilized by an organization’s applications and services. However, there are many threats that you should mitigate during the development and API update process. Let’s explore those threats:
Unnecessary Data Exposure
Sometimes an API responds to a request by providing an excess amount of data that is not relevant to the request. Although the application or service will only show the specific data that has been requested, there are chances that it can expose sensitive information publicly.
Broken Authentication
Broken authentication is a serious threat to API security because a cyber attacker can exploit this opportunity. An attacker can compromise the authentication process and act as a user to gain entry.
Poor Asset Management
Poor asset management is another serious threat to API security and it mainly occurs due to quick development and deployment of APIs. Since new APIs or updates are deployed without proper documentation, it exposes and ghosts many endpoints.
The security team can’t properly understand how old the API is while applying security measures.
Broken Object-Level Authorization
Broken object-level authorization severely affects API security because it occurs when the API request can modify the data that shouldn’t have access. If an attacker gets such access, they can easily access different user’s accounts and jeopardize API security.
Lack of Rate Limiting and Resources
API endpoints are mostly internet-facing and a lack of rate limiting to the number of requests can lead to cyberattacks like DoS or brute-force attacks. The attacker can overwhelm the API with a large chunk of requests, leading to disruption in the operation and a slowdown in performance.
Injection Risk
Injection risks occur when the API request data isn’t properly validated and this allows the cybercriminal to launch SQL injection attacks in an attempt to access the data. Besides, it also gives attackers the chance to execute malicious codes to hamper the web application or service.
Broken Function-Level Authorization
This is a serious issue that originates when there is a poor implementation of POLP due to complicated access control policies in place. When this situation arises, it gives an opportunity for the attacker to execute sensitive commands for special user accounts.
Top API Security Best Practices
API security serves as an important requirement for most organizations using APIs in their web application and microservices as they face various threats.
Just implementing API security won’t be sufficient, your organization needs to implement certain best practices that help in bolstering the defense against all types of API attacks. Here are those best practices:
Enforce Authentication and Authorization
To minimize the attack surface on APIs, it is important for the organization to manage and control the access to APIs. Since API provides access to certain functions, it is important for organizations to enforce authentication and authorization because it will validate the user and device.
Usually, multi-factor authentication, OAuth 2.0, or Jason web tokens are utilized for authenticating API requests and defining grant types to ensure users can access specific API resources. Zero trust principles or POLP are followed for authorization as it will enable users to have access to resources they require.
Leverage SSL/TLS Encryption
Another practice that every organization should follow is leveraging SSL/TLS encryption to safeguard API traffic. In most API requests and responses, the traffic might carry various sensitive information, especially customer financial data.
An attacker through an MITM attack or eavesdropping the network traffic can easily interpret the traffic and gain access to those sensitive data. However, enforcing SSL/TLS encryption can secure the API traffic and protect them from eavesdropping or social engineering attacks.
Validate All the API Data
All the API data should be validated correctly through a regular validation process from the server side. Even if the data is cleansed correctly, it is important that they should be validated at regular intervals because it will help in preventing injection and cross-site scripting attacks.
You can utilize Chrome DevTools to assess the API’s data flow and check anomalies that will provide an indication of cyber threats.
Apply Zero Trust Control
It is essential for every organization to have access management for API because it will ensure the security of all the data and resources. Access management should be applied with zero-trust control because it will ensure the least privilege control.
As a result devices or users will have minimal access to API resources or data they need to perform specific tasks. Importantly each API request will be validated based on the case and prevent unauthorized access to the API function.
Perform Regular Security Tests and Risk Assessment
As more and more APIs are deployed for business operations, the number of cyberattacks on these APIs is also increasing. Performing security tests and risk assessments at regular intervals can help the security team identify all the vulnerabilities, misconfigurations, and underlying security threats that can expose the APIs.
Regular testing will provide complete visibility of API security posture and enable the team to implement specific security controls to manage the possible API security risks.
Only Necessary API Data Should Be Shared
In many situations, API responses may carry an entire database of sensitive information and expect the client application to filter out the specific data that needs to be viewed.
This excess sharing of sensitive data enables cyber attackers to steal sensitive information and get access to the resources the API uses. Policies and controls should be implemented to ensure that only required information needed by API response should be shared.
Keep a Log of APIs in the API Registry
Every organization should discover all the APIs and keep a log of them in the API registry to make sure there is no silo in the overall API security.
Moreover keeping a log of APIs will help in defining characteristics, meeting compliance requirements, and helping during forensic analysis after a security incident. It will also be helpful for third-party developers who might use them in their web applications or microservices.
Conduct Regular Updates and Patch Vulnerabilities
Vulnerabilities in APIs serve as one of the biggest threats and it arises from both internal and external sources. A vulnerability can arise for many reasons and on many occasions, it inherits the vulnerabilities from other dependencies.
However, conducting regular updates and patching those vulnerabilities once they are detected will help your organization prevent most of the threats. Moreover, regular updates help in closing gaps and eliminate any chance for attackers to exploit them.
Perform Continuous Monitoring
One of the best ways to prevent automated attacks on API especially those that are publicly accessible is by performing continuous monitoring. Ensure all the APIs are continuously monitored because it will help the team identify any suspicious activity that can lead to a cyberattack.
In most cases, APIs are designed to facilitate seamless interaction between two programs but it is often exploited by attackers. However continuous monitoring can mitigate any possible attack.
Store API Keys in Environment Variables
API keys are widely used for identifying and verifying access to a web application or microservices. However, API keys are more vulnerable than authentication tokens so developers should combine them in web application codes or application source trees.
Having API keys embedded in the application code can expose them completely so secret or API keys management should be utilized. It will not only protect those API keys but help in managing them.
Introduce Threat Detection and AI to API Monitoring
For real-time monitoring of the API, it would be a smart move for organizations to introduce AI-enabled behavioral analysis and threat detection. It will help the organization to seamlessly monitor API traffic and understand user interaction with the API.
Thus, developers will be able to make changes to their security checking process and feed the information to threat detection tools for finding anomalous activity. While considering AI-enabled API monitoring, your organization should predefine the rules and policies to ease the identification process.
Involve API Gateways
There are many APIs that are designed for public usage and this situation often exposes numerous functions to the customers. Moreover, scanning those APIs can also expose a lot of information regarding network infrastructure.
Thus it is important that an organization should use an API gateway that will protect the API by enforcing API key management, rate limiting, and API request filtration. The API gateway serves as a bridge between APIs and the users and ensures every request is filtered.
Utilize a WAAP Solution
The type of attacks thrown at APIs vary largely and with time it is evolving rapidly. From abusing API’ functionality to exploiting vulnerabilities, an API can face a wide range of threats.
A WAAP or web application and API protection solution can be an ideal choice for every organization using a lot of APIs. The primary purpose of WAAP is to identify and prevent attacks from exploiting vulnerability and utilize encryption as well as access management to identify issues.
Get a Complete Visibility of Secure API Usage
To get complete visibility into API security, it is vital to include the third-party APIs. One should go through all the third-party API function’s documentation, process, and security aspects. When you get complete visibility of the API you will use in the application or services; it will help give you a better understanding and assist in properly securing them.
Final Words
API-related threats are changing rapidly, making good API security a critical priority for every organization. To protect your APIs and ensure smooth application performance, it’s essential to adopt advanced strategies, implement best practices, and stay active against new threats.
By following the API security best practices outlined in this article, you can strengthen your organization’s defenses, protect sensitive data, and maintain the trust of your users. Staying ahead in the challenging cyberspace requires a commitment to continuous improvement and vigilance in API security.
