Implementing Security for Serverless Deployments

Welcome to the seventh chapter of our comprehensive guide on AWS security. In this chapter, we will focus on serverless computing and its unique impact on security within AWS environments. We aim to equip you with the knowledge and skills needed to navigate the distinct security landscape presented by serverless architectures. we will begin by demystifying serverless computing, exploring its benefits, challenges, and how it compares to traditional microservices. Next, we will delve into the function-based design paradigm, focusing on the granularity and composition of serverless functions, along with their inherent stateless nature.

As we progress, we will bring the concept of event-driven communication into sharp focus. Understanding this is crucial as we transition into a detailed discussion on event-driven security mechanisms, covering topics from event sources and schema validation to data encryption.

We will then proceed to...

Introduction to serverless security

As we transition from the concept of microservices, which we discussed in the previous chapter, it is essential to understand that serverless architectures are not just an evolution but a specialized form of microservices. While microservices have their own set of security challenges, serverless introduces a new landscape of security considerations that are both unique and complex. This section aims to delve into these aspects before getting more in-depth into specific areas of serverless security.

What is serverless?

First, let’s demystify things around serverless. Serverless is a cloud computing execution model where cloud providers automatically manage the infrastructure. In serverless computing, developers write code that is executed in response to events, such as HTTP requests, database modifications, or even changes in system state or periodical execution. Behind the scenes, the cloud provider dynamically allocates resources to...

Event-driven security

Event-driven architectures have emerged as the bedrock of contemporary cloud-native applications, especially those leveraging serverless platforms. While these architectures offer many benefits, such as scalability and decoupling, they also present unique security challenges. This section aims to offer an in-depth exploration of these challenges, focusing on strategies for mitigation, with a specific emphasis on EventBridge.

Event sources

First and foremost, it is essential to identify and secure the event sources. These could range from API requests and message queues to cloud storage and databases. Ensuring that only authorized entities can generate events is the first line of defense in event-driven security. This often involves implementing proper authentication and authorization mechanisms, both at the event source and destination levels.

Event schema validation

EventBridge’s schema registry allows event schemas to be defined, which serve...

Securing Lambda functions

Securing Lambda functions is a critical aspect of cloud-native applications running in serverless architectures. Lambda functions can be triggered by various services and external sources. This makes them a potential entry point for malicious activities. This section aims to provide a comprehensive guide to securing Lambda functions, focusing on best practices and AWS-specific features.

Code integrity

Code integrity is the foundation of any secure application. Ensuring that the code running in your Lambda functions is exactly what you expect it to be is crucial for preventing unauthorized modifications and injections. Here, we will delve into several methods to ensure the integrity of your Lambda function code.

Code signing

Code signing is a crucial method for verifying the integrity of your Lambda function code. By attaching a digital signature, Lambda ensures that only signed and authorized code packages are deployed. This process adds a robust...

Summary

In this chapter, we delved into the world of serverless computing, a paradigm shift that brings both opportunities and challenges to cloud architecture. We kicked things off by introducing the concept of serverless, its benefits and challenges, and how it compares to traditional microservices. We then discussed the security considerations that are unique to serverless architectures, covering a wide range of topics from responsibility domains and zero-trust architecture to data encryption and compliance. We also explored event-driven security mechanisms, diving into event sources, schema validation, and data encryption. This chapter concluded with a deep dive into securing Lambda functions, discussing code integrity, environment variables, runtime protection, and monitoring, among other key security aspects.

As we move on to the next chapter, we will explore the complex yet crucial topic of multi-tenancy in shared environments, focusing on secure design patterns and techniques...

Questions

Answer the following questions to test your knowledge of this chapter:

1. What is event sourcing and how does it bolster security?
2. How does code signing enhance Lambda security?
3. How does versioning contribute to Lambda security?
4. What are the risks and limitations of the default Lambda network configuration?

Answers

Here are the answers to this chapter’s questions:

1. Event sourcing involves capturing a series of events that represent state changes in an application, creating an immutable audit trail. This is invaluable for security analysts who may need to rewind the system state to analyze past security incidents.
2. Code signing verifies the integrity of your Lambda function code by attaching a digital signature. AWS Signer is used to create a signing profile, and Lambda validates the signature during deployment. This ensures that only authorized and unaltered code is deployed.
3. Versioning allows you to publish immutable versions of your Lambda function, providing a clear history of what code was running at any given time. This is crucial for auditing and compliance.
4. The default network settings for Lambda functions come with certain limitations, such as the absence of network isolation and limited access control options. They also lack support for advanced networking...

Further reading

The following resources offer further insights and best practices for serverless security:

• AWS Whitepaper – AWS Serverless Multi-Tier Architectures with Amazon API Gateway and AWS Lambda: https://docs.aws.amazon.com/pdfs/whitepapers/latest/serverless-multi-tier-architectures-api-gateway-lambda/serverless-multi-tier-architectures-api-gateway-lambda.pdf
• AWS Whitepaper – Security Overview of AWS Lambda: https://docs.aws.amazon.com/pdfs/whitepapers/latest/security-overview-aws-lambda/security-overview-aws-lambda.pdf
• Serverless Security Challenges and Countermeasures, by Abdirahman Mohamed (2021): https://towardsaws.com/serverless-security-challenges-and-countermeasures-8a94f7d7babe