What Is API Security? Threats, Tools, and Best Practices in 2025 | USCSI®

What Is API Security? Threats, Tools, and Best Practices in 2025 | USCSI®

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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www. nstitute.org uscsi What is API SECURITY? Threats, Tools, and Best Practices in 2025
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute What is API Security? API or Application Programming Interface refers to the features in software that allow it to interact with other applications and software. Currently, they have become a fundamental component of modern software so that organizations can easily exchange data across services, platforms, and applications. “ ” APIs have an important role to play in modern application architecture but with advancements in technology, they have become a preferred target for various kinds of cyber-attacks. Since APIs work as the backend framework for different kinds of systems and services, it becomes important to secure APIs and secure sensitive data they transfer. According to the 2024 State of API Security Report by Salt Security, have 55% of organizations delayed application rollout because of API Security issues. This document highlights the importance of API security, various API vulnerabilities, and different ways to secure it. For every cybersecurity enthusiast, it will serve as a great resource to enhance their knowledge about API and API Security. API security refers to the practice of protecting APIs from evolving and emerging cyber threats. APIs are also as vulnerable as other applications, networks, or servers. APIs can be easily accessed by outsiders and thus possess greater cybersecurity risks. Therefore, it is an important component of web application security. IN THE PAST 12 MONTHS, API SECURITY INCIDENTS THE HAVE MORE THAN DOUBLED. - 2024 Salt State of API Security Report
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute Importance of API Security Cyber-attacks are becoming more common for apps, microservices, or serverless architectures that depend on APIs for their core functions. APIs have now become an integral part of businesses. They serve as backend frameworks for all kinds of applications, including mobile apps, web apps, SaaS, partner-facing, or customer-facing apps. However, they are at great risk attributing to several factors as described by Traceable. These APIs are responsible for the transfer of huge amounts of sensitive data which makes it mandatory for partners to increase the security of APIs and improve their incident response measures. By integrating API security practices into their cybersecurity measures, organizations can prevent attacks like XSS and SQL injections and prevent data breaches. API security ensures their APIs and the programs they support perform securely. Source: Traceable.ai API are a security risk because they expand the attack surface across all layer of the technology stack. The volume of APIs make it difficult to prevent attacks 0% 60% 10% 20% 30% 40% 50% 58% 54% 57% 53% 55% 56% 2023 2025 Traditional security solutions are not effective in distinguishing legitimate from fraudulent activity at the API layer.
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute API Various Threats API security is highly important, because if not done properly, then they can facilitate attackers to gain unauthorized access to data and disrupt operations. In the following graph we can see the main causes of data breach because of API exploitation, as reported by Traceable State of API Security Report 2024. A few of them have been explained in this section. Source: Traceable API Security Report 2025 DDoS Fraud Abuse and Misuse Known Attacks Brute Force Business Logic Attack Unknown Attacks (Zero-Day) Account Takeover Enumeration Other 10% 0% 20% 40% 60% 80% 2023 2025 38% 37% 29% 31% 29% 25% 23% 27% 23% 23% 18% 17% 16% 17% 16% 3% 10% 19%
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute Some of the most common forms of API vulnerabilities and threats include: AUTHENTICATION-BASED ATTACKS In this, attackers try to steal passwords to gain access to API servers MAN-IN-THE-MIDDLE ATTACKS Hackers intercept API requests and responses and steal or modify data CODE INJECTIONS Also known as injection attacks, attackers inject malicious scripts/codes through API request that displays weaknesses in the API interpreters SECURITY MISCONFIGURATIONS In this attack, sensitive user data and system information are exposed because of default configurations, incorrect HTTP headers, or overly permissive CORS DENIAL-OF-SERVICE (DOS) ATTACK DoS attack refers to sending several requests to APIs to crash or slow down the server. BROKEN OBJECT LEVEL AUTHORIZATION (BOLA) ATTACKS It occurs when hackers manipulate the object identified at API endpoints leading to increased attack surface and unauthorized access to data
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute The security of APIs mostly depends upon authentication and permission. However, additional features can be implemented to enhance their security. Here are the different steps in which API security works: STEP 5 STEP 4 STEP 3 STEP 2 STEP 1 How does API Security Work? AUTHENTICATION Authentication is the first step to verify the user and grant access to API. AUTHORIZATION After successful authentication of legitimate users, they are authorized to use a set of data or perform actions. REDUCTION OF VULNERABILITY ATTACKS APIs should also have features to minimize the application's vulnerability to threats during API calls. DEFENSE AGAINST ATTACKS The use of prepared statements can help protect API from SWL injection. RATE-LIMITING This feature helps prevent DoS attacks by limiting the number of requests users can make
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute API Security Types and Tools As per 2024 Salt State of API Security Report only of professionals think that their security 20.9% tools and solutions are very effective whereas think it is not very effective. However, 13% organizations cannot ignore the importance of efficient API security tools to protect their apps and software. The following are some widely used security systems and tools for API security: These are some of the popular tools and ways that check authentication, authorization, and other components of security to protect APIs. Open Authorization or OAuth API Managers Security Assertion Markup Language (SAML) Transport Layer Security (TLS) Multi-factor Authentication Source: Salt API Security Report 2024 53.6% 6.3% 20.9% 13.0% 6 . 3 % How effective are your existing security tools in preventing API attacks? I do not know 6.3% Not at all effective 6.3% Not very effective 13.0% Very effective 20.9% Somewhat effective 53.6%
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute Challenges of API Security Implementing an efficient API security requires addressing some challenges as follows: REST API Security vs. SOAP API Security REST and are two main architectural styles that modern APIs use. SOAP SOAP APIs are known to be more secure as per their design while REST APIs can be made more secure based on how they are implemented and the selected architecture for their development. VS SOAP Simple Objects Access Protocol or SOAP is the type of API that uses digital signatures and encryption of the data in XML-format and applies security at the message level. REST Representational State Transfer is known to be the most popular architectural style, and it powers most of the modern web APIs today. It uses HTTP/S as the transport protocol and JSON format for data transfer. APIs work in a different way than normal applications and software. Thus, their security planning and solution is quite unique compared to others. Some SaaS is available only as an API and create security challenges for organizations as they have to handle huge data volumes. All applications are of course different; however, APIs require proper security measures by considering their unique designs. Sometimes APIs introduce new file formats and structures that facilitates hackers to perform attacks like XSS and SQL injection APIs need a very high level of security and monitoring, otherwise they would lead to offering access to backend functions if not securely properly.
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute Methods of API Security Testing Cybersecurity specialists use various methods to manually test their APIs and identify security vulnerabilities. Some of the popular methods are: Top API Testing Tools in 2025 PARAMETER TAMPERING TEST this is done using hidden form fields. Use the browser element inspector to find hidden fields and experiment with varying values to check how the API reacts. COMMAND INJECTION TEST In API inputs try to inject operating system commands. By observing how it performs on the server you can identify the API's vulnerability to injection attacks API INPUT FUZZING TEST Check for indications that the API is returning an error, is getting crashed, or is processing inputs incorrectly to find input fuzzing. UNHANDLED HTTP METHODS TEST You will get errors if the API server doesn't support any HTTP method. These tools are used widely to test API security Postman Swagger Jmeter SoapUI Karate Fiddler Fiddler
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute API Security Best Practices It is critical for businesses to implement API security. But with API security best practices, they can minimize the risk and damage to their APIs. In the graph below we can see various factors that obstruct successful implementation of API security strategy such as budget, workforce, time, etc. Addressing these can help implementation of API security successful. What is the biggest obstacle keeping you from implementing an optimal API security strategy? Fiddler Other than that, organizations must follow the best API security practices as mentioned below. Implementing secure authentication and authorization protocols Using proper encryption technologies to secure data Validating inputs to protect APIs against malicious data Using rate-limiting techniques to protect resources against DoS and brute force attacks Quotas and throttling also help restrict API calls Installing API gateways to restrict API access and enhance network security, especially in the case of open APIs Regular security audits Following these steps and processes, organizations can enhance the security of their APIs and protect manipulation of sensitive data. Source: Salt API Security Report 2024 BUDGET ENTERPRISE RESOURCES/PEOPLE DEFINED STRATEGY TOOLING/SOLUTIONS COMPETING PRIORITIES TIME OTHERS 21.76% 20.92% 20.08% 13.39% 9.62% 6.69% 4.18% 3.35% 0.00% 5.00% 10.00% 15.00% 20.00%
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. www.uscs .org institute APIs are the essential components of modern applications facilitating communication with other applications, servers, networks, and software. They form the backend process of transferring huge amounts of data from applications to servers and vice versa. Therefore, is paramount for all organizations in today's highly interconnected world API security where cyber threats are looked at every point. This guide gives an overview of detecting and protecting against vulnerabilities as well as discussing best API security practices. Following these will definitely help your organization protect against all kinds of API vulnerabilities and keep your data protected. Conclusion
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  ® © Copyright 2024.United States Cybersecurity Institute (USCSI ). All Rights Reserved. ENROLL IN CERTIFICATION NOW The United States Cybersecurity Institute ® (USCSI )is a world-renowned cybersecurity certification body offering the best-in-the-world certifications for students and professionals around the globe across industries. Whether a beginner looking to step on cybersecurity career path or a seasoned expert, it validates their cybersecurity expertise to ace this domain.