SAA-C03 Exam Dumps : AWS Certified Solutions Architect - Associate (SAA-C03)

The most secure and least operationally intensive method is to configure cross-account access using resource-based policies on the S3 bucket. This allows trusted external AWS accounts (consulting agencies) to securely access the S3 data without the need to manage user credentials or build additional infrastructure.

Options A and B pose security risks. Option D increases operational complexity and violates least privilege by managing external users inside your AWS account.

The IAM policy includes two statements:

1️⃣ Allow ec2:TerminateInstances on all resources

2️⃣ Deny ec2:TerminateInstances if the request does NOT come from:

192.0.2.0/24

203.0.113.0/24

AWS IAM policy evaluation rules state:

Explicit Deny always overrides Allow.

A request must meet all applicable conditions in the policy to be granted.

aws:SourceIp condition applies when IAM actions are invoked via the public AWS APIs.

In this scenario, the administrator is not originating the request from one of the allowed CIDR blocks, so the Deny condition is triggered, overriding the Allow statement.

Therefore, the operation is blocked with:

403 AccessDenied: explicit deny

This matches the behavior described in the AWS IAM Policy Evaluation Logic used in the Security Pillar of the Well-Architected Framework:

Explicit Deny > Allow > Default Deny

IP-based Conditions restrict API calls originating outside approved network ranges

Options A/B/C do not accurately reflect this explicit Deny condition behavior.

Amazon Elastic File System (Amazon EFS) is a fully managed, elastic, shared file system that can be mounted concurrently by multiple EC2 instances across multiple Availability Zones. EFS automatically grows and shrinks as files are added or removed, providing seamless scalability for unpredictable and growing storage needs. It supports simultaneous access from multiple compute resources, making it ideal for applications where several EC2 instances must read and write to the same data set concurrently. EBS volumes cannot be shared across multiple Availability Zones, and S3 Glacier is intended for archival and infrequent access, not for active, hourly data analysis.

Reference Extract from AWS Documentation / Study Guide:

"Amazon EFS provides a scalable, fully managed elastic NFS file system for use with AWS Cloud services and on-premises resources. It can be mounted to many EC2 instances across multiple Availability Zones and is ideal for shared data scenarios."

Source: AWS Certified Solutions Architect – Official Study Guide, Storage Solutions section; Amazon EFS User Guide.