APIs allow easy communication between and among systems, applications, and services. They also allow organisations to connect to their activities, share data, and enhance user experiences. However, while APIs easily connect between systems, they also expose them to various vulnerabilities which attackers can gain unauthorized access, steal sensitive information, or even disrupt services.

Security engineers should enforce strict access restrictions, validate inputs, and continuously monitor API traffic for abnormalities. Prioritizing security allows organizations to reduce risks, meet laws and regulations, and maintain user trust.

This blog explores API security, why it is important, and common security threats and vulnerabilities. Learn more about API security standards and REST vs SOAP vs GraphQL.

What is API Security?

API security is the process of protecting APIs against risks, unauthorized access, and data breaches. It includes implementing authentication, authorization, encryption, and monitoring methods to protect data and ensure that APIs operate safely within an organization's infrastructure.

APIs serve as communication routes between applications, systems, and services, and they handle sensitive data like personal information, financial transactions, and business processes. Without proper protection, APIs become vulnerable to attacks like credential stuffing, injection attacks, and unauthorized data access.

Why API Security is Important?

An API vulnerability can expose an entire system to serious threats like unauthorized data access, credential theft, and denial-of-service assaults. Here's why API security is important:

Protects Sensitive Data

APIs manage personal information like user credentials, financial data, and business transactions. Attackers use weaknesses to gain access or steal sensitive data without proper security measures. Data breaches can cause financial loss and reputational damage. Use encryption and data masking to protect sensitive information from unauthorized access.

Prevents Unauthorized Access

Source:cyberpedia

Weak authentication and incorrectly configured access controls allow attackers to bypass security measures. Unauthorized users can gain access to private data and they can perform malicious activities. Using authentication mechanisms like OAuth 2.0 and OpenID Connect improves access control. Role-based access control (RBAC) ensures that only authorized users can access specific API endpoints. Enforcing strict permission requirements reduces the risk of unauthorized access.

Reduces Cyber Threats

APIs are common targets for cyber threats like credential stuffing, injection attacks, and denial-of-service (DoS). Attackers use API vulnerabilities to attack systems, steal data, and interrupt services. To reduce risks, security engineers should use threat detection, input validation, and rate restriction methods. Continuous monitoring and logging allow accurate detection of malicious actions. Proactive security measures reduce the risk of attacks.

Ensures Regulatory Compliance

Regulatory frameworks like GDPR, HIPAA, and PCI-DSS mandate strict security measures when handling sensitive data. Failure to comply with these regulations can result in substantial fines, legal consequences, and reputational harm. API security helps organizations meet regulations by implementing encryption, authentication, and access controls. Security audits and frequent evaluations help ensure that regulatory standards are met.

Common API Security Threats and Vulnerabilities

APIs are common targets for attacks because they allow easy communication between systems. Here are some common API security threats and vulnerabilities organizations should know to protect their systems:

Broken Authentication and Authorization

Weak or poorly built authentication techniques allow attackers to gain access to user sessions, steal passwords, or bypass authentication controls. If APIs use weak passwords, improper multi-factor authentication (MFA), or improper token handling they become vulnerable to attacks. They can become vulnerable to attacks like privilege escalation and unauthorized data exposure. Improper role-based access control (RBAC) or missing authorization allows attackers to change API requests and get access to organizational data.

Lack of Rate Limiting and Throttling

APIs without rate restriction lead to automated attacks like brute force, denial-of-service (DoS), and API scraping. Attackers use uncontrolled API endpoints to overload services and steal large amounts of data. Implementing rate limitation and throttling methods reduces the number of requests per user or IP address. Security engineers should use deep logging to track authentication failures, access attempts, and malicious activity.

Injection Attacks

APIs that do not check user inputs are vulnerable to injection attacks, like SQL injection, command injection, and XML External Entity (XXE).  Attackers insert malicious code into API calls to change databases, execute unauthorized commands, or get access to confidential information.  Low input validation and parameter sanitization can lead to injection attacks. To reduce injection attacks, use strict input validation, parameterized searching, and input sanitizing.

Security Misconfigurations

Insecure API configurations, like exposed debug endpoints, redundant HTTP methods, or missing security headers, expose attack vectors. Attackers use misconfigurations to get access to private information, perform unauthorized actions, or manipulate API behavior. Common misconfigurations include incorrect CORS settings, a lack of TLS encryption, and the use of default passwords. Security engineers should follow strict setup best practices, regularly audit API settings, and remove unused or unnecessary endpoints.

Improper API Logging and Monitoring

APIs with improper logging and monitoring are challenging to detect and respond to security events. Without continuous monitoring, organizations can fail to detect unauthorized access, data breaches, or API abuse. Security engineers should use accurate logging to log authentication failures, access attempts, and suspicious activity. Using SIEM systems improves API threat detection and incident response capabilities.

API Security Standards

Following API security standards allows organizations to maintain compliance and prevent security breaches. Here are some common API security standards:

OAuth 2.0

OAuth 2.0 is an industry-standard protocol for secure authorization that allows applications to access APIs without revealing user credentials. The authentication method implements both access tokens with strict permission controls to minimize credential theft.  The authorization framework OAuth 2.0 includes multiple permissions such as authorization codes and client credentials to support different application functions. Security measures become stronger through token expiration and refresh methods implementation.

OpenID Connect (OIDC)

OpenID Connect allows for both authentication and authorization and ensures secure user identity verification and access management. It allows single sign-on (SSO) by asking users to prove their identities with ID tokens provided by an identity provider (IdP). OIDC helps to increase security by preventing unauthorized access to APIs and makes authentication easier for users. Implementing OIDC reduces the risk of password-related attacks while improving user experience.

Transport Layer Security (TLS)

Source: Freepik

TLS secures communication between APIs and clients by encrypting data in transit. TLS deployment safeguards requests and responses to protect them from exposure incidents, unauthorized modifications and MitM assaults. The API communication protects through TLS versions 1.2 and 1.3 while security weaknesses exist in TLS versions 1.0 and 1.1. API authentication receives an enhancement through the implementation of mutual TLS (mTLS) since it makes both server and client prove their identity during communication.

JSON Web Token (JWT)

JWT is a flexible and independent token format which is used to secure API authentication and authorization. It allows APIs to check user identities and permissions without storing session data on the server. To prevent tampering, JWTs carry data including signed and optionally encrypted claims. Token leakage, long token lifespan, and weak signature validation are security risks that can lead to unauthorized access and data breaches.

OWASP API Security Top 10

The OWASP API Security Top 10 includes risks like broken authentication, excessive data exposure, weak permissions, and more. Following these rules will help organizations to reduce API risks and improve security postures. Security engineers should regularly check APIs against OWASP standards, implement security measures, and perform penetration testing to protect data.

REST API vs SOAP API vs GraphQL

REST, SOAP, and GraphQL have different methods for structuring and exchanging data.

REST API

REST APIs allow clients and servers to communicate using regular HTTP methods (GET, POST, PUT, and DELETE). They are stateless, which means that each request includes all required authentication and authorization information. Security risks include the exposing of sensitive data because of over-fetching, a lack of rate limitation, and improper authentication measures. Implementing OAuth 2.0, enforcing input validation, and securing API endpoints with HTTPS helps to reduce security threats.

SOAP API

SOAP APIs use XML-based messaging and follow strict communication guidelines. They have built-in security methods like WS-Security, that allow message encryption, authentication, and integrity checks. SOAP is widely used in organizations with strong security needs, like financial services and healthcare.  However, they are complex and vulnerable to misconfiguration, which might result in authentication or encryption issues.

GraphQL API

GraphQL allows clients to request required data rather than collecting predefined replies which removes over-fetching and under-fetching issues. However, this flexibility poses security risks like data exposure, complex authorization logic, and denial-of-service (DoS) attacks that are caused by highly nested queries. Implementing query depth limits, authorization checks at the field level, and proper user input validation will help organizations improve security.

Final Thoughts

APIs are a necessary component for all organizations, and API security is also essential.  Weak authentication, insufficient authorization, excessive data exposure, and misconfigurations are all possible attack vectors to protect essential data and organizational processes.

Securing APIs includes continuous monitoring, continuous attack detection, and automated risk mitigation. Akto helps organizations identify vulnerabilities, implement security standards, and improve API security. With easy compatibility and continuous protection, Akto improves security posture without affecting operations. Schedule a demo today to learn how Akto can keep your APIs secure from new threats.