From startups to large-scale enterprises, more businesses are moving their applications to the cloud, and for many of them, serverless applications offer the ideal solution. The term “serverless” doesn’t mean that servers aren’t involved – it signifies that businesses don’t need to manage, maintain, or administer servers themselves. Instead, the responsibility is handed over to the cloud service provider.
Amazon Web Services (AWS) is one of the most popular platforms for deploying serverless applications. However, while AWS manages the underlying infrastructure, security remains a shared responsibility. This means that businesses must still take steps to secure their applications, even when they’re running in a serverless environment. Today we will discuss the best practices for securing a serverless application on AWS.
Understanding Serverless Security on AWS
Before diving into the best practices, it’s beneficial to understand what serverless security entails.
Serverless architectures are built around functions – ephemeral bits of code that execute in response to certain triggers. In AWS, these are known as AWS Lambda functions. While AWS manages the underlying infrastructure, the code within the function and the triggers that initiate them are the responsibility of the developers. Therefore, when we talk about serverless security, we are primarily referring to securing these functions and their triggers.
The primary areas of focus for serverless security on AWS are the function code, access management, data security, and application security.
Securing the Function Code
AWS Lambda functions are the building blocks of your serverless application. Ensuring the security of these functions is an essential part of securing your application.
The first best practice is to write secure code. This involves following coding best practices, avoiding the use of insecure libraries or APIs, and regularly reviewing and updating your code to fix any security vulnerabilities.
Secondly, consider using an AWS-native tool like CodeGuru, which can automatically review your code for security vulnerabilities and provide recommendations for improvements.
Finally, remember to limit the permissions of your Lambda functions. Each function should have the minimum permissions needed to perform its task. This is known as the principle of least privilege and is a fundamental aspect of cloud security.
Managing Access with IAM
Access management is a critical aspect of securing your AWS serverless application. AWS provides a service called Identity and Access Management (IAM) which allows you to control who can access your AWS resources and what they can do with them.
The best practice here is to implement least privilege access policies – only grant the necessary permissions to users, applications, or services for them to perform their duties.
Additionally, consider using IAM roles instead of sharing AWS credentials among your team. IAM roles provide temporary credentials that are automatically rotated, providing an added layer of security.
Lastly, regularly audit your IAM policies and permissions. This will ensure that only the necessary persons or services have access to your resources and help you identify and rectify any overly permissive policies.
Securing Data in Serverless Applications
When it comes to data security in serverless applications, there are several practices you should consider.
First, encrypt sensitive data at rest and in transit. AWS provides several tools for this, including the Key Management Service (KMS) for managing encryption keys and the AWS Certificate Manager for handling SSL/TLS certificates.
Second, consider implementing a data loss prevention (DLP) strategy. This might involve using a service like Amazon Macie, which uses machine learning to automatically discover, classify, and protect sensitive data.
Lastly, implement data backup and recovery strategies. Even in a serverless environment, data loss can still occur, so having a robust backup and recovery strategy is crucial.
Protecting Serverless Applications with Application Security Practices
Application security is an important part of securing serverless applications on AWS. This involves protecting your applications from threats like injection attacks, cross-site scripting (XSS), and other common web application vulnerabilities.
One of the best practices here is to use AWS WAF, a web application firewall that helps protect your applications from common web exploits.
Additionally, consider implementing a security information and event management (SIEM) solution. AWS offers Amazon GuardDuty, a managed threat detection service that continuously monitors for malicious activity and unauthorized behavior.
Finally, regularly monitor and audit your application activity. AWS offers services like AWS CloudTrail and Amazon CloudWatch for logging and monitoring, which can help you detect and respond to security incidents quickly.
Securing a serverless application on AWS involves securing the function code, managing access with IAM, securing the data, and protecting the application with security best practices. By following these best practices, you can ensure that your serverless applications on AWS are as secure as possible.
API Gateway Security in Serverless Applications
One of the critical aspects of serverless security on AWS is securing the API Gateway. API Gateway is a service by AWS that acts as a “front door” for applications to access data, business logic, or functionality from your backend services. API Gateway is commonly used with Lambda functions to build serverless applications.
When securing your API Gateway, authentication and authorization are two of the most critical areas to focus on. You should ensure that only authenticated and authorized users can access your API endpoints. AWS provides a service called “IAM roles for Amazon API Gateway”, which allows you to define who can access your API and what they can do with it. This involves setting up IAM roles and permissions, setting up resource-based policies, and using AWS Cognito for user authentication.
Another best practice is to enable API Gateway logging. AWS provides detailed logs of all API Gateway traffic, which can be useful for detecting and investigating security incidents. You can access these logs through services like AWS CloudWatch.
Lastly, consider using AWS WAF with your API Gateway. AWS WAF is a web application firewall that helps protect your API from common exploits like SQL injection and cross-site scripting attacks. It provides a set of SQLi and XSS protection rules that you can apply to your API Gateway to increase its security.
With the rapid shift towards serverless computing, securing serverless applications has become essential. AWS offers a robust platform for deploying serverless applications, and with the best practices discussed above, you can significantly enhance your serverless security.
From securing the function code with secure coding practices, least privilege principle, and AWS-native tools like CodeGuru to managing access with IAM roles, permissions, and auditing. It’s important to encrypt sensitive data both at rest and in transit using services like Key Management Service (KMS) and AWS Certificate Manager. Implement a data loss prevention strategy using Amazon Macie and a robust data backup and recovery plan.
Secure your API Gateway with proper authentication and authorization, enabling API Gateway logging, and using AWS WAF. Integrate application security practices like Amazon GuardDuty for threat detection and AWS CloudTrail and Amazon CloudWatch for logging and monitoring.
However, remember that serverless security is a shared responsibility. While AWS takes care of the underlying infrastructure security, you are responsible for your application and data security. Regularly review and update your security practices and stay informed about the latest security risks and trends in serverless architecture.
In conclusion, securing your serverless applications on AWS is a continuous process. By following these best practices, you can reduce the potential for security breaches and ensure your serverless applications remain secure, reliable, and efficient.
