Serverless API Security is very crucial aspect in terms of protecting serverless computer architectures, which allows developers to implement code without the need of managing underlying infrastructure. This approach is known Function as a service (FAAS) which facilitates applications to keep scaling actively based on the requirements, but often presents new security challenge.

This blog takes you through fundamentals serverless API security and best practices to secure Serverless API’s.

What is Serverless API Security?

Serverless API Security means protecting the functions, data flows and permissions in a serverless architecture. Serverless systems depend on event driven execution and are stateless, which means they require a unique method to address security risks like misconfigurations, injection attacks and broken authentication mechanisms.

Source: nordicdefender.com

Benefits of Serverless API Security

Serverless API Security provides multiple benefits that improves the overall security and efficiency of serverless computing architectures. Here are some of the benefits:

Minimizes Operational Overhead

Serverless API Security significantly minimizes the operational load on security teams by removing the need to maintain underlying server infrastructure. Since cloud platforms manage server maintenance, updates and patching, security teams can focus on securing application logic, configurations and permissions. This change in responsibilities allows better resource utilization and cost optimization.

Improves Security Posture

Serverless API Security improves the entire security posture by promoting a least privilege access model. This is when each function is allowed only the required access necessary for its operation. This in turn helps in limiting the possibility of damage from compromised functions and reduces the attack surface. Besides this, serverless environments mostly have built in security features like API Gateways and runtime protections which offers protection against threats like injection attacks and unauthorized access.

Supports Scalability and Flexibility

Another key benefit of Serverless API Security is its ability to scale actively as per requirements. As traffic rises, serverless functions automatically allows for scaling to handle the load, and also ensure security measures to scale along with them. This helps in continuous protection without the need of manual interventions from security teams. Apart from this, real time monitoring and logging tools provide proactive threat detection which allows for rapid identification and response to possible security incidents.

Simplifies Vulnerability Management

Serverless API Security helps simplify vulnerability management by providing tools and practices that manage application integrity. Regular vulnerability scans for code and dependencies ensure serverless applications remain protected over time. Besides this, runtime detection tools detect malicious inputs, unusual behavior and limits possibility of threats that improves the overall security posture. This approach helps security teams to focus on addressing risk even before they become incidents.

Improves Access Control and Authentication

Serverless API Security improves access control and authentication by facilitating strong IAM based authentication and role based access control. This enables secure communication between services and users by allowing only necessary permissions to each user and function. Furthermore, integrating with identity services offers a centralized management system for user identities and access. This improves the security and maintains integrity of serverless applications.

How does Serverless API Security Work

Serverless API Security involves securing API’s in a serverless architecture, where backend services run without the need of manually managing infrastructure. Here is a breakdown on how it works:

Initiate User

User sends an HTTP request to the serverless API endpoint. This request gets transmitted over HTTPS, which ensures Transport Layer Security (TLS) encryption. This is initial communication with the serverless infrastructure.

Authenticate API Gateway

The API Gateway will authenticate the request by using methods like JWT tokens or IAM credentials. It implements authorization policies and rate limiting to avoid Denial of Service (DOS) attacks. Malicious and vulnerable inputs are filtered through a web application firewall (WAF).

Invocation of Function

A serverless function will be activated to process the validated request. It works under a least privilege IAM function, which limits access to necessary resources only. Input validation happens to completely restrict injection attacks. (eg. command injection or SQL)

Secure the Data

The function communicates with resources using encrypted connections (TLS). Data at rest is secured using encryption through management services and access is thoroughly scanned to reduce exposure of sensitive information.

Deliver Response

The function creates a response (eg. JSON payload) and returns it through the API gateway. This response is encrypted in the transit by using TLS which ensures confidentiality and sensitive data is restricted to prevent leakage.

Monitor and Log Activities

Details of execution are captured in consolidated logging systems. Metrics and traces help in allowing anomaly detection and identification of threat. Alerts are configured to respond to the security irregularities.

Challenges in Serverless API Security

Serverless API Security introduces unique risks and challenges because of its serverless architecture nature. Here is a breakdown of some of the challenges:

Rise in Attack Surface

Serverless application communicate with many event sources like HTTP APIs, IoT devices, cloud storage, and message queues. Each of these interfaces increases the attack surface which might potentially invite vulnerabilities that cyber attackers can misuse. Suspicious input data from these type of sources can result in injection attacks or other security attacks if not properly validated.

Undefined Network Perimeter

Serverless environments does not have a well defined perimeter, unlike traditional architectures with clear boundaries that are protected by firewalls. This makes it challenging to implement traditional security measures and it increase the dependence on application layer security like API gateways and encryption.

Ephemeral Functions

Serverless functions are ephemeral, which means they typically execute for seconds or milliseconds before shutting down. This short lived duration nature makes it difficult for the traditional security measures like rate limiting and session management. Besides this, auditing and monitoring are difficult because of short lived infrastructure.

Misconfigurations

Misconfigured cloud services or serverless settings can lead to excessive exposure of sensitive data or might result in creating entry point for cyber attackers. Common challenges include insecure API endpoints, improper timeout controls, unsecured secret storage that might lead to security attacks like Denial-of-Service (DOS) or Denial-of-Wallet (DOW).

Complex Permission Management

Serverless architecture mostly consist of interconnected microservices with complex permission requirements. Misconfigured IAM roles or over permission can result in privilege escalation or unauthorized access across various functions that increases the risk of security attacks.

Best Practices for Serverless API Security

Best practices have to implemented by security teams to mitigate and prevent security attacks for Serverless API Security. Here’s a break down of some of the best security best practices:

Use API Gateways as Security Buffers

API Gateways play as intermediaries between users and serverless functions by providing a layer of protection. They implement HTTPS protocols, maintain authorization, authentication and perform rate limiting to alleviate abuse. API Gateways can reduce the attack surface and provide security against injection attacks, data breaches and unauthorized access.

Apply Least Privilege Access

Serverless functions must operate with minimal permissions for each function where it ensures only necessary access to resources essential for their operations. Review and adjust the permissions regularly to maintain a least privilege model. IAM roles must be carefully configured to limit access to only necessary resources.

Employ Immutable Infrastructure

Immutable infrastructure plays an important role in reliable system management. Deploy functions and configurations as immutable entities which cannot be altered after the deployment. Any updates are implemented only by redeploying newer versions. This approach removes configuration drift and minimizes the risk of unauthorized modifications.

Incorporate Circuit Breakers for Resilience

Circuit breakers are very important for building resilient systems. Implement circuit breaker patterns to detect and handle failures well within the serverless functions. This helps prevent failures and consistently maintain system stability. Efficient implementation ensure that application recover effortlessly from faults.

Reduce Attack Surface with Microservices Segmentation

Break down applications into smaller isolated microservices. This segmentation limits potential security attacks, prevents attackers from easily getting access. It also helps in simplifying monitoring and improves the overall resilience of system. Such segmentation is an important strategy in modern application development.

Final Thoughts

Securing Serverless APIs is crucial for modern applications in current digital sphere. As organizations rapidly adopt serverless architecture, implementing strong security measures becomes an essential aspect for security teams. Akto is a comprehensive API security platform designed to help organizations proactively secure their APIs throughout the DevSecOps pipeline. It maintains continuous inventory of APIs, offers uninterrupted monitoring, testing for various vulnerabilities and identify runtime issues. Its extensive feature list includes customizable test libraries for rigorous security assessments, to provide uncompromised and all round security and protection for serverless APIs. This helps security teams ensure resilience against security attacks and maintain secure operational environment.

Book a demo today and Experience unmatched comprehensive API Security from Akto.io!