What is Cloud API Security? A Complete Guide

What is API Security?

API Security is a general term that refers to the practices and protocols designed to protect your API (or Application Programming Interface) from API threats. Security has a lot of elements and is best thought of as a comprehensive strategy.

It’s a delicate balance for security professionals as they seek to mitigate risks like data breaches and unauthorized access while ensuring that legitimate users experience no obstacles. 

 This article will delve into key principles for reinforcing API security, tackling challenges like blocking attacks and strengthening vulnerabilities, and focusing on maintaining seamless data exchange and support for authorized users.

What is Cloud API Security

Cloud APIs carry unique risks and challenges, requiring attention to the services they offer and the complex cloud environments they operate within. To add another layer of complexity, Cloud APIs often involve multiple stakeholders and third-party services, which can increase the overall risk and complexity of the security posture.

Cloud API protection faces common risks like compromised user authentication and authorization alongside unique threats from external dependencies, including implementation flaws, unauthorized APIs, credential leaks, and data breaches.

Effective cloud security demands specialized strategies, such as cloud-specific access controls and encryption, to prevent malicious data theft or exploitation of flaws, thorough API lifecycle management to prevent deprecation and adoption issues, and robust control over external API usage.

Key Concepts in Cloud API Security

Cloud API Security, essentially a decentralized take on traditional API Security, follows many of the same guidelines and faces similar risks in guarding against malicious activity and threats. The key difference lies in addressing these concerns across various services, both ephemeral and permanent. Let’s take a closer look at API security first.

API Security Fundamentals

In order to implement API security effectively, you’ll want to keep the following fundamentals in mind:

Data Encryption

Securing data is crucial, and the best way to do this is by using strong encryption. Encryption is the process of taking data and scrambling it in a way that only trusted users with the right key can use that data. The more data you hold, the wider your attack surface, so starting with good encryption right away is key to keeping your data and APIs safe from attacks. 

Data Encryption in Transit

APIs transmit data from one system to another and this data should be adequately secured during transit. Transport Layer Security, or TLS, is an industry-standard solution that can encrypt data as it’s exchanged, ensuring protection from eavesdropping, tampering, and man-in-the-middle attacks. TLS is essential to protect sensitive data and ensure communication security.

Data Encryption at Rest

Once data has been transferred, it must be secured to ensure that any potential exfiltration is mitigated. In Cloud APIs, this is especially important as there’s no real physical separation between data processing and storage. There are many encryption-at-rest options; choose one that’s easy to maintain, as security needs constantly evolve.  Authentication and Authorization Mechanisms

Protecting sensitive data is as much about securing the data as it is about securing access, ensuring only authorized users can access critical information and functions. Accordingly, implementing proper access control policies is a vital step in setting a strong security posture. There are two types of access controls in this domain – authentication and authorization.

What is Authentication?

Authentication is making sure that a user is who they say they are. If a user says that they are an admin named AdminUser01, the system must ensure that this person is who they say they are. This can take a variety of forms, including the use of data and hardware keys or authentication tokens that establish the user is accessing the system in a way that is similar to how it has been accessed before. This can also include things such as passwords and other factors.

What is Authorization?

Authorization, on the other hand, is proving that a user has the right to access what they are trying to access. This can be accomplished through a variety of mechanisms, including role-based access control, object-level access control, and more. Broken object-level authorization (BOLA) and broken function-level authorization (BFLA) are very common issues, even in otherwise secure authorization implementations – this is a great example of the fact that authorization should be comprehensive and complimentary. Good enough in one area is not good enough for the whole system.

Fortunately,  there are many authorization solutions in the market, and open authorization standards such as OAuth offer a relatively plug-and-play solution at scale.

Multi-factor Solutions

 It’s crucial to avoid single points of failure in security systems. Authorization should encompass knowledge, possession, and inherent traits of the user, known as multi-factor authentication.

API Security Risks and Threats

Common API Security Threats

In API security discussions, it’s essential to examine the types and scope of vulnerabilities.. First, there are issues of authorization and authentication. These issues stem from inadequate user control and overly permissive access, leading to data and function exposure.

Next, there is the general category of data integrity and process security. Injection attacks, such as SQL injections and cross-site scripting (XSS) issues, can be used to exploit vulnerabilities in APIs. Injection attacks can exploit user input to bypass authentication, threatening API security despite protective measures. Man-in-the-middle attacks can be used to hijack interactions, infiltrating the system with otherwise legitimate traffic.

There are also major concerns with misconfiguration and vendor dependency.  Misconfiguration can undermine even the most secure systems, rendering strong authentication useless. Often, this isn’t due to your actions; choosing a poorly performing vendor can be as detrimental as implementing insecure systems.

With so many risks, how can developers begin to form a plan for tackling this issue?

OWASP Top Ten

Luckily, The Open Worldwide Application Security Project, or OWASP, has put together a list called the OWASP Top Ten. While this list is not exhaustive, the OWASP API vulnerabilities list is nonetheless representative of the most common threats to which APIs are exposed.

The OWASP Top Ten divides the most common security issues into the following categories:

A01:2021-Broken Access Control

This category of security issues includes services that have broken access control, allowing users to access data without proper security systems standing in the way.

A02:2021-Cryptographic Failures

This is when cryptographic implementations are flawed, resulting in data exposure or – in serious cases – full system compromise.

A03:2021-Injection

Injection is when data is forced into the system through transit failure, poor sanitation, etc. Attacks of this kind can expose the underlying data and systems and often come from poor external vendor integration or sanitation procedures.

A04:2021-Insecure Design

This type of issue comes from poor design processes, including the implementation or poor development paradigms, codebase structures, and security design.

A05:2021-Security Misconfiguration

This is a broad category, but it is unfortunately very common. Poor configuration can lead to even powerful solutions being rendered basically ineffective, exposing data and creating additional vectors for attacks.

A06:2021-Vulnerable and Outdated Components

This refers to using outdated or unpatched software components with known vulnerabilities. Attackers can exploit these known weaknesses if not updated or patched promptly.

A07:2021-Identification and Authentication Failures

This used to be called “Broken Authentication,” but this has also been expanded to include identification issues. This category covers issues where authentication mechanisms are improperly implemented, allowing attackers to compromise passwords, keys, or session tokens.

A08:2021-Software and Data Integrity Failures

This includes vulnerabilities that occur when software updates, critical data, or CI/CD pipelines are not verified, allowing attackers to inject malicious code or manipulate data.

A09:2021-Security Logging and Monitoring Failures

This category highlights the lack of proper logging, monitoring, and alerting mechanisms that can help detect security breaches. Without these, attackers can operate undetected.

A10:2021-Server-Side Request Forgery

SSRF vulnerabilities occur when an attacker is able to induce a server-side application to make HTTP requests to an unintended destination, potentially leading to unauthorized actions or information disclosure.

Secure API Design and Development

The best way to ensure you have a good security posture is to start early. Adopting some general processes for secure API design and development is a great way to ensure a culture of security.

Secure Coding Practices

Secure coding practices baked into the application development process itself, such as input validation and error handling, can help prevent common API security threats. Ensuring that the data entering the system has been vetted and sanitized can ensure that even attacks using what seems like valid traffic can be stopped in their tracks, preventing the abuse of your internal authentication and authorization systems.

Using secure protocols, such as HTTPS and TLS, can help protect data transmitted through APIs. This ensures your data is secure in transit and can be protected from man-in-the-middle attacks that might hijack the traffic for nefarious purposes.

Be Defensive

Approaching your system with defense in mind can help create a more secure implementation for your APIs. Rate limiting and quotas can help prevent denial-of-service attacks and abuse in ways that are often invisible to the average end user, giving you a strong defensive posture from day one.
Using JSON Web Tokens (JWTs) and other secure authentication mechanisms can help protect API endpoints. Pairing this with a Zero-Trust paradigm, where everything is validated and nothing is intrinsically trusted, can ensure that these systems are cross-validated and secured in their own context.

API Traffic Management and Monitoring

Managing API Traffic

A huge first step in securing your traffic is managing traffic generation. Managing traffic involves controlling and regulating the flow of requests and responses between APIs and clients, as well as using load balancers to prevent overload and distribute that traffic across services. This can prevent DDOS attacks and other attacks focused on overwhelming the system.

Implementing caching and content delivery networks (CDNs) can help improve API performance and reduce latency. In doing this, attacks that focus on overwhelming systems and forcing errors can effectively be drastically reduced in efficacy, as the potential damage done by any one attack vector is mitigated.

Monitoring Traffic

Of course, it’s not good enough to just manage the traffic – you also need to monitor the API events coming into the system. Monitoring traffic involves tracking and analyzing API requests and responses to detect security threats and performance issues.

Implementing real-time monitoring and alerting can help detect and respond to security incidents quickly. In essence, if your API is a secure stronghold, monitoring is a tower by which you can survey the land and ensure your stronghold is not beset by hidden enemies.

API Discovery 

Part of making sure your APIs are secure is knowing that they exist. Of course, in an ideal world we would know of every API ever built within our company. However, the reality is that manual API inventories are not always accurate or up to date, which could lead to untested and potentially vulnerable APIs within your attack surface. This is where API discovery tools can come in handy to ensure that every API, including those created maliciously or forgotten by accident, is included in testing and API security efforts. Tools like StackHawk actually do this at the code level by searching code repositories for APIs and then marking them to be tested, helping to improve security for all APIs hosted on the cloud or otherwise.

A crucial concept in cloud systems is the ephemeral nature of services and databases, which are continuously created and decommissioned. This ongoing change brings familiar API and data security challenges, along with the crucial need for compliance, accurate record-keeping, and constant awareness in a fast-paced setting.

Let’s consider credential stuffing. In a typical API, the best way to mitigate such threats is to rate limit inputs for credentials and to utilize systems that flag compromised assets. In a cloud API, however, you must be able to do this for services that are being created by the minute – sometimes numbering in the hundreds.

In the cloud environment, typical issues from the development lifecycle are significantly intensified. Weak authentication is problematic on its own, but this issue escalates dramatically when managing hundreds of microservices or data sources, complicating monitoring even further. In such an environment, poor API security posture exacerbates the problem to the nth degree.

Cloud services also typically use a wide spread of protocols and approaches. REST APIs might work closely with SOAP (or Simple Object Access Protocol) APIs, gRPC APIs, WebSockets, and much more. These services might rapidly appear and disappear, and the API risks that are inherent with such complicated systems can rapidly become even harder to track or be aware of.

To that point, cloud security is largely about making API security intrinsic to the integration and development process. Unsafe consumption can be prevented when developers are mindful of the practice. Web application and API risks can be mitigated with more secure development. Solutions deployed early on such as federated token-based authentication, can ensure the ability to properly authenticate users even when the system is incredibly complex.

Best Practices for Securing Cloud APIs

When securing Cloud APIs, it’s critical to implement a series of best practices to protect against unauthorized access and ensure data integrity. Here’s a list of API security best practices for securing your cloud APIs:

Authentication and Authorization

• Use Strong Authentication: Implement strong, multifactor authentication mechanisms to verify the identity of users and services.
• Leverage OAuth 2.0: Utilize OAuth 2.0 protocol for delegated authorization, providing tokens instead of sharing credentials.
• Employ Role-Based Access Control (RBAC): Define roles and privileges to limit access to API functionalities based on user roles.
• API Keys: Use API keys for simpler scenarios with caution, ensuring they are not exposed in client-side code.

Encryption and Data Protection

• Enforce TLS: Use Transport Layer Security (TLS) to encrypt data in transit between the client and your API.
• Sensitive Data: Avoid transmitting sensitive data unless necessary, and if you must, use additional end-to-end encryption.
• Data at Rest Security: Protect data at rest through encryption and secure key management practices.

Traffic Management

• Rate Limiting: Implement rate limiting to prevent abuse and mitigate DDoS attacks.
• Throttling: Use throttling to control the amount of incoming traffic, ensuring equitable resource utilization and prioritizing legitimate users.
• Quotas: Enforce quotas to limit the number of requests a user can make within a specified timeframe.

Monitoring and Logging

• Audit Logs: Ensure detailed logging for all API access and transactions for future audits and anomaly detection.
• Monitoring and Alerting: Use real-time monitoring tools to track API usage and performance, with automated alerts for suspicious activities.
• Anomaly Detection: Implement systems for detecting and responding to abnormal API usage patterns that may indicate a breach.

API Gateway and Management

• API Gateway: Use an API gateway to manage API requests, enforce policies, and provide an additional layer of security.
• Microservices Security: When using microservices architecture, secure each individual service and API accordingly.
• Version Management: Properly manage API versions to phase out older, potentially less secure endpoints.

Patching and Maintenance

• Regular Updates: Keep all your API components and dependencies up to date with the latest security patches.
• Vulnerability Scanning: Perform regular vulnerability scans to identify and remediate security weaknesses.
• Dependency Management: Track and manage third-party libraries and dependencies, ensuring they are secure and kept up-to-date.

Input Validation and Output Encoding

• Strong Input Validation: Reject any API requests with unexpected or dangerous input to prevent injection attacks.
• Output Encoding: Encode data sent via APIs to prevent cross-site scripting (XSS) and other injection attacks.

Error Handling

• Standardize Error Responses: Use generic error messages to prevent attackers from inferring excessive details about the backend system.
• Exception Management: Properly handle exceptions to prevent leakage of stack traces or other sensitive information.

Documentation and Education

• API Documentation: Provide clear documentation for the API, outlining secure usage best practices for consumers.
• Developer Training: Educate developers on secure coding practices and security considerations specifically related to API development.

Compliance and Legal Aspects

• Regulatory Compliance: Ensure your API meets all relevant regulatory compliance standards, like GDPR, HIPAA, or PCI-DSS.
• Data Protection Laws: Understand and adhere to the data protection laws applicable to the geographical locations where your service operates.

Implementing these best practices is essential to securing Cloud APIs. Regularly reviewing and updating security measures is critical in adapting to new threats and maintaining strong API security.

Remember that there are many standards and solutions that have evolved in the cloud environment. Cloud security frameworks and standards, such as the Cloud Security Alliance (CSA) and the Open Web Application Security Project (OWASP), can help ensure cloud API security using time-tested approaches to protect sensitive information and data.

Choosing the Right API Security Solution

It is vital that you choose the right API security solution. Once you have data exposed, the cat is out of the bag, so it’s important to get this right the first time.  API security solutions encompass API gateways, security proxies, and cloud-based services. A thorough evaluation of their features and capabilities as a unified system aids in selecting an optimal solution tailored to your APIs, environment, and requirements.

No one solution is inherently secure, so considering your security as a complete offering – while considering the scalability, performance, and cost of API security solutions – can help ensure that you choose a solution that meets your needs and budget.

Compliance Considerations for Cloud APIs

 Cloud APIs pose unique challenges in regulatory and compliance frameworks. Although they function similarly to regular APIs, their decentralized and distributed processing complicates compliance issues. This is particularly relevant under the General Data Protection Regulation (GDPR), where cloud services might use resources both within and outside GDPR jurisdictions, serving global users.

Much of this complexity arises from the difficulty in precisely auditing where data is stored and in what form. Compliance with industry standards, such as HIPAA for healthcare or PCI-DSS for payment processing, requires maintaining an audit trail for resources. However, this becomes particularly challenging in cloud environments where resources are dynamically activated and deactivated based on demand. 

In cloud contexts, maintaining observability and auditability is even more critical. Strong authentication protocols such as OAuth and SAML contribute to this, mainly by facilitating access auditing. However, auditing data storage requires robust logging and monitoring systems at the data level to ensure security.

Federated services can do a lot of the heavy lifting here, allowing for ample tracking with authenticated systems that are federated and delegated, allowing for a centralization of information and a decentralization of operation.

How StackHawk Can Help with Cloud API Security

Infrastructure is only one piece of the puzzle when it comes to deploying APIs in the cloud. At the code level, ensuring that applications are secure is also crucial. StackHawk’s modern dynamic API security testing (DAST) platform allows developers to test locally or in CI/CD, allowing them to detect and remedy potential security issues lurking within their applications.

Testing before the code can hit production servers running on the cloud is an essential first step in cloud API security. Experience StackHawk firsthand by signing up for a 14-day free trial today.