1.3.2. Shared Responsibility: Customer's Role (SysOps Focus)

💡 First Principle: The customer is responsible for "security in the cloud," securing their data, applications, and configurations within AWS services, like OS patching, network controls, and IAM permissions.

Scenario: When deploying an application on EC2 instances, you, as a SysOps Administrator, are responsible for managing OS patches, configuring security groups, and ensuring data encryption.

In the AWS Shared Responsibility Model, the customer's responsibility is for "security in the cloud." For SysOps Administrators, this means securing everything they put into and configure within the AWS Cloud, specifically concerning the operational environment and application runtime.

Key Customer Responsibilities ("Security in the Cloud") for SysOps:

• Operating System (if using EC2): Guest OS patches, security updates, firewall configurations on EC2 instances (AWS Systems Manager Patch Manager).
• Network Configuration: Security Groups and Network ACLs for application endpoints and traffic flow control.
• IAM Permissions: Configuring IAM roles and policies for users and automated processes using the Principle of Least Privilege.
• Data Security: Encrypting application data (at rest and in transit), data classification (Amazon Macie), and managing S3 bucket policies (e.g., preventing public access unless intended).
• Application Security: Ensuring the application code itself is secure and vulnerabilities are addressed.
• Configuration of Managed Services: Properly configuring security settings for services like Amazon S3 bucket policies or DynamoDB table access.

⚠️ Common Pitfall: Neglecting to apply OS patches or misconfiguring Security Groups, assuming AWS handles these aspects for EC2 instances.

Key Trade-Offs: The level of control you desire over your infrastructure (e.g., EC2 vs. Lambda) directly impacts the scope of your "security in the cloud" responsibilities.

Reflection Question: How does failing to manage OS patches on your EC2 instances or misconfiguring security groups directly demonstrate a failure in your responsibility for "security in the cloud" within the Shared Responsibility Model?