DEV Community

Cover image for Understand the AWS Shared Responsibility Model

Understand the AWS Shared Responsibility Model

๐ŸŒ… Exam Guide: Cloud Practitioner
Domain 2: Security & Compliance
๐Ÿ“˜Task Statement 2.1

A New Dawn, A New Domain

New year, new youโ€ฆ and new domain on the exam. While youโ€™re setting goals like drink more water, AWS is setting goals like keep the cloud from catching fire. The catch: some security tasks are yours.

Welcome to the AWS Shared Responsibility Model.


๐ŸŽฏ What Is This Task Testing?

You must understand:

  • The AWS shared responsibility model
  • The major components of the model
  • What AWS is responsible for
  • What the customer is responsible for
  • What is shared
  • How responsibilities shift depending on the service (e.g., Amazon EC2 vs Amazon RDS vs AWS Lambda)

๐Ÿง  The AWS Shared Responsibility Model

The simplest way to remember it:

  • AWS is responsible for security OF the cloud
  • Customers are responsible for security IN the cloud

This model helps define who handles which security controls, reducing confusion and improving risk management.

1)โ˜๏ธ AWS Responsibilities (Security OF the Cloud )

AWS is responsible for protecting the underlying infrastructure that runs AWS services.

AWS typically handles:

  • Physical security: data centers, buildings, access controls, surveillance
  • Hardware and infrastructure: servers, storage, networking equipment
  • Virtualization layer: host OS/hypervisor for many services
  • Core networking: and foundational services that support the platform

If itโ€™s about data centers, hardware, or the base cloud infrastructure, itโ€™s almost always AWS.

2) ๐Ÿง‘โ€๐Ÿ’ป Customer Responsibilities (Security IN the Cloud)

Customers are responsible for what they deploy and configure on AWS, including controlling access and protecting their data.

Customers typically handle:

  • Identity and access management (IAM): users, roles, policies, MFA
  • Data protection: encryption choices, key management decisions, data classification
  • Network configuration: security groups, NACLs, VPC configuration
  • OS and application management: patching, hardening when applicable
  • Customer data: what you store, how you store it, who can access it
  • Logging and monitoring configuration: what you enable tracking and alerts on

If itโ€™s about permissions, misconfiguration, data exposure, or application security, itโ€™s usually customer.

3) ๐Ÿค Shared Responsibilities (Depends on Context)

Some areas are shared because both AWS and the customer play a role.

Common shared areas:

  • Configuration management: AWS provides secure tools, customers must configure them correctly.
  • Patch management: AWS patches infrastructure, customers patch OS/apps when they manage them.
  • Awareness and training: AWS provides documentation, customers ensure staff follow best practices.
  • Incident response: AWS secures the platform, customers respond to events in their accounts/workloads.
  • Compliance: AWS provides compliant infrastructure, customers must architect and operate compliantly.

If โ€œAWS provides the capability, customer must enable/configure it,โ€ thatโ€™s usually shared.

4) ๐Ÿ”„ How Responsibilities Shift by Service Type

Your responsibility changes based on whether youโ€™re using IaaS, PaaS, or serverless/managed services.

A. Amazon EC2

EC2 is closer to โ€œyou run a server,โ€ so you manage more.

AWS handles: physical facilities, hardware, underlying infrastructure

Customer handles: guest OS patching, software installs, configuration, application security, data, IAM, network controls

With EC2, you are responsible for the operating system and above.


B. Amazon RDS

RDS is a managed database service so AWS takes over more operational tasks.

AWS handles: database engine patching/maintenance (service-dependent), backups features, underlying infrastructure

Customer handles: database access controls, network exposure, encryption settings, parameter choices, data, IAM

You donโ€™t manage the database host like you would on EC2, but you still control data security and access.

C. AWS Lambda

Lambda is serverless so no servers to manage.

AWS handles: servers, OS, runtime infrastructure, scaling, availability of the service

Customer handles: function code, IAM permissions, secrets management, event/input validation, data protection

You focus on code + permissions + data, while AWS runs the platform.


Quick Comparison

  • EC2: customer manages OS + patching + runtime + app
  • RDS: AWS manages database platform, customer manages data + access + configuration
  • Lambda: AWS manages servers/OS/scaling, customer manages code + IAM + data

โœ… Quick Exam-Style Summary

  • AWS Shared Responsibility Model:
    • AWS = security OF the cloud
    • Customer = security IN the cloud
  • Responsibilities shift by service:
    • more managed/serverless = more AWS responsibility
    • more infrastructure control (like EC2) = more customer responsibility

Additional Resources

Shared Responsibility Model

Top comments (0)