It’s an expanding cloud landscape, and application programming interfaces (APIs) have become a connecting force in modern cloud infrastructure, with SaaS applications using these conduits to send and receive information between tools, apps, and IoT devices — and to ensure that data is shared where necessary.
However, the rise of API usage requires increasing diligence to ensure their security. This article will examine the core best practices of API security, including why many organizations should consider a dedicated API security solution.
APIs ensure that enterprises can connect best-of-breed point solutions together into a unified technology stack by enabling different software systems, applications, or services to communicate and share data seamlessly. APIs provide standardized methods for requesting and exchanging data, letting disparate tools work together.
They’re immensely valuable in cloud computing, enabling the orchestration of services across diverse environments and multiple providers. They offer flexibility in building cloud-native applications, improving efficiency, and enabling policy enforcement across cloud services.
Additionally, APIs facilitate scalability, security, and real-time management of resources, making them crucial for a modern, agile enterprise.
No matter the type, security teams should be able to discover and catalog all APIs that communicate with the internet.
That need for flexibility and scalability has meant a proliferation of APIs in cloud architectures today. As cloud computing and microservices advance, smaller, independent services replace monolithic applications. However, each will require its own APIs to communicate. This service-oriented architecture increases the number of APIs as every microservice communicates with others via APIs. Add external services, from payment gateways to analytics tools or CRMs, and multiple APIs of different types have become commonplace.
APIs add complexity beyond their type. It’s also worth noting that other factors add to their complexity, from a lack of visibility to misconfigurations, excessive data exposure, inconsistent access control, third-party risks, and complex dependencies.
In addition, individual security concerns stem from different API types.
Private APIs are not meant for consumption outside the enterprise. These are typically created within engineering teams to connect custom systems or applications used internally. Because they’re inaccessible from the broader internet, these APIs are often the easiest to secure with cloud security tools and network gateways. Their primary security challenge is access control and authentication since they’re designed for internal use with restricted access.
As the name indicates, a “public” API provides broad access to certain features or data of a service, application, or platform. They’re accessible to external developers, third-party applications, and the general public. These APIs tend to be used to extend the functionality of a product or service, with third-party developers building applications or integrations on top of them. These APIs create the biggest security risk because of their public availability. Key challenges include rate limiting and throttling (which control the number of API requests a client can make within a specific time frame), data exposure, input validation and injection attacks, and encryption.
These APIs are similar to public APIs, but the difference lies in access. Partner APIs are only made available to specific partner organizations, like customers, affiliates, or collaborators, to control access to different data or services. Permission is often managed with some form of authentication. The native integrations from SaaS applications fall into this category. Their more pressing security challenges include trust and authentication, granular access control, compliance and data protection, and monitoring and auditing.
Third-party APIs are valuable because of the functionality they deliver. Developers use these to save time in development and incorporate specific capabilities or data quickly. Yet they come with an inherent lack of control over the external service, and organizations using these services must trust the security of their providers — but also mitigate security risks like data privacy and compliance, API reliability and availability, access control, and security monitoring and auditing.
Each of the above types of APIs can operate on any of the standard communication protocols, adding another layer to their basic security requirements of access controls, encryption, monitoring, and validation mechanisms to mitigate vulnerabilities. The four most common are:
Regardless of protocol, organizations should be able to view all APIs in one place for a bird’s eye view of how their APIs communicate with the internet.
The Representational State Transfer (REST or RESTful) protocol is the most common, with 85% of APIs using this protocol. It’s lightweight and stateless (it doesn’t store user sessions), making it ideal for web and mobile applications, where speed and ease of use are key. It’s also easy to create, relying on standard, widely known HTTP protocol and easy-to-read data formats like XML and JSON. The simplicity of REST APIs makes them accessible but leaves them prone to misconfigurations. Securing REST APIs means:
Simple Object Access Protocol (SOAP) APIs have stricter standards than REST APIs, and are typically used where reliability, transaction security, and strict communication standards are crucial. It operates with more rigid protocols than REST, often in scenarios that require formal contracts between services, like financial and healthcare services and government data exchanges.
With SOAP APIs, security considerations include its built-in WS-Security, which adds layers for message integrity and confidentiality. That means that:
RPC allows applications to execute procedures or methods on another system over a network. It’s used where direct, low-level communication is required, such as internal services or systems management. RPC is powerful but risky because of its direct nature, allowing fast, efficient communication between systems.
This protocol comes with its own security concerns, including:
GraphQL is a more modern API protocol designed for efficiency and flexibility, allowing clients to specify the data they need from a service and reducing over-fetching and under-fetching issues common with REST APIs. It’s widely adopted for front-end applications where flexibility in data querying is a priority.
GraphQL empowers non-developers to write and understand data queries, but because of that power, it is often limited in scope. Security tools can reduce GraphQL APIs to their single HTTP endpoint without looking at queries individually.
Specific security concerns with this type of API include:
As APIs proliferate, they present an expanded attack surface, making API security an indispensable component of an organization’s security strategy. Yet, the different types of APIs and their diverse protocols make a monolithic “API Security Strategy” a myth. Instead, multiple approaches are required to safeguard sensitive data, maintain compliance, and mitigate risks.
However, there are some foundational best practices to be aware of in API security.
Without an accurate inventory, shadow APIs or undocumented endpoints may remain vulnerable to exploitation. Tools that dynamically catalog and map APIs in real time help security teams maintain a clear understanding of their API landscape, identifying risks like internet exposure, data sensitivity, and documentation drift, thus mitigating security threats proactively.
Discover and catalog API endpoints, regardless of type, in real-time, ensuring comprehensive visibility and reducing risks from undocumented or shadow APIs.
Effectively securing APIs requires continuous identification and management of risks. Leveraging real-time monitoring tools, teams can assess vulnerabilities like insecure internet communication, outdated components, and API drift, where documentation and implementation fall out of sync. Detecting these issues early helps ensure APIs stay aligned with security standards throughout their lifecycle.
View weaknesses such as internet communication and drift detection in APIs.
Encrypting API traffic is a critical step in securing all types of APIs. Encrypting data both at rest and in transit means sensitive data remains unreadable to attackers, limiting the impact of any intercepted or extracted data. Using automated tools to detect and encrypt API communications helps organizations stay compliant with standards like GDPR and HIPAA, too.
Identifying unprotected data reduces risk and helps organizations stay compliant.
API requests must be authenticated using modern protocols like OAuth or JWT, which work to securely transmit information or login without sharing credentials across the internet. It’s easier to ensure that robust authentication and authorization are protecting APIs by integrating runtime insights to verify identities and enforce granular access policies, ensuring the right permissions are enforced at every endpoint.
Enable strong authentication and fine-grained access controls to protect APIs from unauthorized access at scale.
To protect APIs from being overwhelmed with excessive requests, implement rate limits and throttling. Controlling the frequency of API requests prevents abuse like Denial-of-Service (DoS) attacks or accidental overconsumption of resources by legitimate users. With rate limits and throttling, APIs remain responsive and secure under high loads.
Enable rate limits and throttling to lower the chance of malicious requests.
The widespread use of APIs has made them attractive targets for cyber attacks, and has meant that organizations need to do more to secure their APIs than institute a static strategy and step aside. Achieving effective API security means monitoring emerging threats, implementing proactive defenses, and adapting to sophisticated attacks.
A few of the modern challenges facing API security processes include:
