Securing APIs: Approaches to mitigate risks in modern web applications

APIs (Application Programming Interfaces) are the foundation of modern web applications. They enable seamless communication between different systems, apps, and services, making them essential in today's digital economy. However, as businesses increasingly rely on APIs, they also expand their attack surface, creating more opportunities for cybercriminals. Securing APIs is no longer optional; it's a necessity for protecting sensitive data, maintaining customer trust, and ensuring operational stability.

The importance of API security

With API traffic growing, securing these interfaces becomes critical to protect sensitive data, maintain operational continuity, and uphold compliance. According to a survey report by Salt , 95% of their respondents experienced problems with API security, out of which 23% experienced a breach. Business leaders must prioritize API security to manage these risks and protect their organizations' reputations and assets.

Traditional web security works by protecting a well-defined network perimeter with static protocols and browser-based verification to identify potential threats, such as cross-site scripting or DDoS attacks. However, API security differs significantly, as APIs create numerous endpoints with varying protocols and evolving request formats, making them more challenging to secure. Unlike traditional networks, APIs are accessed by diverse clients—such as mobile apps, services, or software components—that don't rely on browsers, rendering traditional verification methods ineffective. This dynamic, decentralized nature of APIs demands specialized security measures that adapt to rapid changes and handle non-browser-based interactions efficiently.

Risks of unsecured APIs for organizations

Poorly secured APIs leave them vulnerable to attacks by malicious actors. Some of the most common types of API attacks include:

• Man-in-the-middle (MitM) attacks, where attackers intercept data transmitted between APIs and their consumers, stealing or manipulating sensitive information.
• Injection attacks, where SQL or script injections exploit vulnerabilities to manipulate or retrieve unauthorized data.
• Broken object-level authorization (BOLA), where unauthorized users access or manipulate objects they shouldn't have permissions for.
• DDoS (Distributed Denial of Service) attacks, which cause APIs to flood with traffic, overwhelming the system and causing service outages.
• API Key Theft, where attackers gain unauthorized access by stealing poorly secured API keys, allowing them to impersonate legitimate users.

Security teams face greater pressure to monitor API activity, detect threats in real time, and respond quickly to incidents, making API security a necessary component for effective ITOps. Some of the risks include:

• Data exposure: APIs may unintentionally expose excessive data to users or developers. Without proper data filtering, sensitive information like personal details or financial data can be leaked, increasing compliance risks and potential breaches.
• Lack of authorization controls: Weak authorization controls allow unauthorized users to access data or functions they shouldn't. Misconfigured permissions can expose APIs to unauthorized access, increasing the likelihood of data leaks or system compromise.
• Injection and scripting attacks: APIs are susceptible to SQL injection, cross-site scripting, and other code-injection attacks. Attackers use these methods to access, modify, or delete data, leading to potential operational disruptions or data breaches.
• Resource exhaustion and rate limiting: APIs lacking rate limits can be overwhelmed by repeated requests, leading to Distributed Denial of Service (DDoS) attacks. Such attacks can exhaust resources and disrupt service availability, impacting user experience and operational stability.
• Inadequate logging and monitoring: Without sufficient logging and monitoring, API-related threats can go unnoticed. This lack of visibility limits the ability of security teams to identify and respond to suspicious activities, increasing the risk of prolonged breaches.

The Trello data breach in 2024 serves as a valuable reminder of the importance of robust API security. In January of 2024, Trello faced a security incident where publicly accessible user data from over 15 million accounts was scraped and offered for sale, which included names, usernames, and email addresses. The incident highlighted how publicly available information could be combined with previously compromised data, potentially leading to targeted phishing and other malicious activities.

Best practices for API security

Securing APIs requires a well-rounded approach that aligns security protocols with business objectives. For CXOs and business leaders, this means adopting strategies that not only address immediate vulnerabilities but also build a robust foundation for long-term protection. Below are key practices that help safeguard APIs while ensuring operational resilience and customer trust.

Strengthen authentication and authorization

Authentication and authorization are the cornerstones of API security. By ensuring that only verified users and systems can access APIs, organizations can significantly reduce the risk of unauthorized access. Implementing modern standards like OAuth 2.0 and OpenID Connect ensures secure token-based authentication. Multi-factor authentication (MFA) adds an additional layer of protection, making it harder for attackers to compromise accounts. Role-based access control (RBAC) further enhances security by limiting user access to only the resources necessary for their roles, thereby minimizing the potential damage from compromised accounts.

Encrypt data and ensure secure handling

Data transmitted via APIs often includes sensitive information that can be a goldmine for attackers. Encrypting this data using protocols like Transport Layer Security (TLS) is essential to prevent interception during transmission. Equally important is the secure handling of data at rest—masking or redacting sensitive fields can mitigate the risks of accidental exposure or leaks. For organizations in regulated industries, regular audits and compliance checks ensure that data protection standards are maintained, minimizing legal and reputational risks.

Apply rate limiting and throttling

Unrestricted API access can strain resources and open the door to abuse, including Distributed Denial of Service (DDoS) attacks. Rate limiting and throttling mechanisms help organizations manage API traffic effectively. By setting thresholds on the number of requests a user or system can make within a specific timeframe, businesses can prevent service disruptions caused by malicious or excessive requests. Dynamic throttling provides an additional advantage by adjusting limits based on real-time traffic patterns, ensuring consistent performance during peak usage or suspected attacks.

Conduct regular API testing and assessments

APIs evolve rapidly, especially in environments that embrace DevOps practices, making regular testing critical for identifying vulnerabilities. A robust testing strategy should include static and dynamic application security testing (SAST/DAST) to uncover code flaws and vulnerabilities. Penetration testing simulates real-world attack scenarios, providing deeper insights into potential weaknesses. Incorporating automated testing during the development phase allows organizations to identify and fix issues early, reducing the risk of deploying vulnerable APIs.

Monitor and log API activity continuously

Visibility into API activity is essential for detecting threats and ensuring compliance with security protocols. Continuous monitoring enables organizations to identify anomalies, such as unusual access patterns or unauthorized attempts, in real time. Maintaining detailed logs of all API interactions not only supports forensic investigations but also helps in identifying patterns that could indicate a larger attack. Automated alerts for suspicious activities allow security teams to respond swiftly, minimizing potential damage.

Deploy API gateways for centralized security

API gateways provide a centralized control point for managing security and performance. By acting as intermediaries between API consumers and backend services, gateways simplify the implementation of authentication, authorization, and traffic management policies. They also offer built-in threat detection and load-balancing capabilities, enhancing both security and scalability. Centralized logging and monitoring through API gateways streamline the tracking of interactions, helping organizations maintain consistent security standards across all APIs.

Leverage AI and automation for threat detection

Modern cyber threats evolve rapidly, often outpacing traditional security measures. AI-powered tools and automation offer a way to stay ahead of attackers. Machine learning algorithms can analyze API traffic patterns in real time, identifying anomalies that may indicate potential threats. Predictive analytics can help organizations anticipate and mitigate vulnerabilities before they are exploited. By automating incident responses, businesses can reduce response times, minimize disruptions, and maintain customer trust even in the face of advanced threats.

Establish a comprehensive incident response plan

Even with robust security measures in place, incidents can occur. Having a comprehensive incident response plan ensures your organization is prepared to act swiftly and effectively in the event of a breach. This plan should outline clear steps for identifying, containing, and resolving incidents while minimizing disruption to business operations. It should also include communication protocols to inform stakeholders, regulators, and customers as required. Regularly testing and updating the incident response plan ensures that your teams remain ready to handle security events and reduce their impact on your organization.

Securing APIs: A strategic imperative

API security is not just about mitigating risks; it’s about safeguarding the backbone of digital transformation. In a world where APIs enable innovation and drive competitive advantage, neglecting their security isn’t an option—it’s a threat to business survival. Organizations that prioritize API security demonstrate a commitment to resilience, customer trust, and future-ready operations.

For business leaders, the message is clear: API security must be treated as a strategic priority, not a technical afterthought. It’s the foundation for thriving in an interconnected digital economy where the cost of inaction far outweighs the investment in robust security measures.