AWS Systems Manager Session Manager provides secure, auditable, and managed instance access without needing to open inbound ports, manage SSH keys, or maintain bastion hosts. It meets all the specified requirements:

1. No exposed management ports: Session Manager uses the SSM Agent, which communicates with the AWS endpoint over an outbound HTTPS (port 443) connection. This eliminates the need to open inbound ports like SSH (22).

2. Full session logging: Session Manager can be configured to log all session activity, including every command and its output, to Amazon CloudWatch Logs or an Amazon S3 bucket, satisfying the compliance need for full logging.

3. Authentication through IAM Identity Center: Access to start a session is controlled by IAM policies. These policies can be attached to an IAM role within an IAM Identity Center permission set, allowing for centralized authentication and authorization.

A. The EC2 serial console is primarily for troubleshooting boot, network, or startup issues and is not intended for full, interactive shell sessions. Its logging is less comprehensive for auditing interactive commands.

B. EC2 Instance Connect requires the instance's security group to allow inbound SSH traffic (port 22) from the EC2 Instance Connect service, which violates the "no exposed management ports" requirement. It also lacks native session logging.

D. This approach explicitly opens remote access ports, which directly violates the core requirement of having no exposed management ports. It is an anti-pattern when a more secure option like Session Manager exists.

1. AWS Systems Manager User Guide, "AWS Systems Manager Session Manager": "Session Manager provides secure and auditable instance management without the need to open inbound ports, maintain bastion hosts, or manage SSH keys." It also states, "You can audit session activity in your AWS account using AWS CloudTrail. You can also log session data to Amazon S3 or Amazon CloudWatch Logs."

2. AWS Systems Manager User Guide, "Setting up Session Manager": Step 2 of the setup process details creating an instance profile with permissions for the SSM Agent. Step 4 covers granting IAM users session permissions, which is the mechanism used by IAM Identity Center permission sets.

3. AWS Security Blog, "How to use IAM Identity Center to provide access to your AWS Systems Manager tools": This blog post outlines the exact pattern described in the correct answer, stating, "You can use IAM Identity Center to provide your users with access to AWS Systems Manager tools, such as Session Manager... This allows you to provide your users with secure access to your instances without having to manage individual SSH keys."

4. Amazon EC2 User Guide for Linux Instances, "Connect to your Linux instance with EC2 Instance Connect": Under "Prerequisites," the documentation states, "The security group attached to your instance must have an inbound rule that allows SSH traffic (TCP port 22) from your IP address or from the IP address range for the AWS EC2 Instance Connect service." This confirms the need for an open port.

This solution correctly addresses all requirements. AWS CloudFormation StackSets with service-managed permissions are designed to deploy resources across an AWS Organization. Enabling automatic deployment ensures that the stack is provisioned in all existing and future member accounts. By configuring a delegated administrator for AWS CloudFormation, the company can manage these StackSets from a designated member account instead of the management account. This adheres to the security best practice of minimizing the use of the management account, fulfilling the principle of least privilege for routine operational tasks.

A. This approach is incorrect because it requires manual intervention to add new accounts, failing the automation requirement. It also unnecessarily uses the management account for a task that can be delegated.

C. While Systems Manager can deploy resources and supports delegated administration, AWS CloudFormation StackSets are the purpose-built, more direct, and idiomatic service for provisioning infrastructure from templates across an organization.

D. This solution fails because it uses the management account, violating the principle of least privilege. Additionally, sharing a runbook does not automatically deploy resources to new accounts without a separate triggering mechanism.

1. AWS CloudFormation User Guide: The section "Register a delegated administrator" states, "You can register a delegated administrator account to create and manage stack sets with service-managed permissions for your organization. By registering a delegated administrator, you can create and manage stack sets from the delegated administrator account." This directly supports using a delegated administrator.

Source: AWS CloudFormation User Guide, "Working with AWS CloudFormation StackSets," section "Register a delegated administrator."

2. AWS CloudFormation User Guide: The section on creating stack sets with service-managed permissions explains the auto-deployment feature. "When you enable auto-deployment, stack instances are automatically deployed to an account when it is added to a target organization or OU." This confirms the capability to deploy to future accounts automatically.

Source: AWS CloudFormation User Guide, "Create a stack set with service-managed permissions," section "Auto-deployment."

3. AWS Organizations User Guide: The guide on best practices for the management account explicitly recommends delegating tasks. "To help you follow this best practice, AWS has created the delegated administrator feature... you can delegate administrative tasks for a specific AWS service to a designated member account."

Source: AWS Organizations User Guide, "Best practices for the management account."

4. AWS Organizations User Guide: The documentation lists services that can be integrated with Organizations, including AWS CloudFormation, which can be registered as a delegated administrator.

Source: AWS Organizations User Guide, "AWS services that you can use with AWS Organizations," section "Services that support delegated administrator."

The solution requires two actions: immediate remediation and long-term prevention. First, enabling Amazon S3 Block Public Access on the bucket or account level immediately removes all forms of public access. This feature overrides any conflicting bucket policies or Access Control Lists (ACLs). Second, to ensure this setting cannot be reversed, a Service Control Policy (SCP) must be applied through AWS Organizations. By creating an SCP with a Deny statement for the s3:PutPublicAccessBlock action and attaching it to the relevant account, you prevent any IAM principal (including the root user) within that account from modifying the Block Public Access configuration. This combination effectively meets both requirements.

A. KMS encryption protects data at rest but does not control network access. Denying s3:GetObject via SCP would block all read access, not just public access.

B. While enabling Block Public Access is correct, denying s3:GetObject via SCP is an incorrect preventive measure as it blocks all object retrieval, which is overly restrictive.

D. Object Lock is a WORM (Write-Once, Read-Many) feature for data immutability and retention; it is not related to managing public access permissions.

1. AWS S3 Developer Guide, "Blocking public access to your Amazon S3 storage": This document explains that S3 Block Public Access provides settings to manage public access to S3 resources. It states, "Amazon S3 Block Public Access can override ACLs and bucket policies so that you can enforce uniform limits on public access to these resources." (See section: How Amazon S3 Block Public Access works).

2. AWS Organizations User Guide, "Service control policies (SCPs)": This guide details how SCPs act as a guardrail to control permissions in an organization. It clarifies, "SCPs are JSON policies that specify the maximum permissions for an organization or organizational unit (OU)... SCPs limit permissions for IAM users and roles in member accounts, including the member account's root user." (See section: Introduction to SCPs).

3. AWS IAM User Guide, "Actions, resources, and condition keys for Amazon S3": This documentation lists all IAM actions for S3. The s3:PutPublicAccessBlock action is defined as granting permission to create or modify the PublicAccessBlock configuration for an account or a bucket, confirming it is the correct action to deny for prevention. (See the Action summary table for Amazon S3).

4. AWS S3 Developer Guide, "Using S3 Object Lock": This source describes Object Lock as a feature to "store objects using a write-once-read-many (WORM) model," which is unrelated to controlling public access. (See section: How S3 Object Lock works).

Amazon Inspector is a vulnerability management service that continuously scans AWS workloads. A specific feature, Amazon Inspector Lambda scanning, is designed to identify software vulnerabilities in Lambda functions and associated layers. It performs two types of scans: one for vulnerabilities in application package dependencies (e.g., libraries) and another for code vulnerabilities within the function's custom code, directly addressing the requirement to scan for code vulnerabilities. This is an automated, continuous process once enabled.

A. Use Amazon Macie.

Macie is a data security service for discovering and protecting sensitive data (like PII) stored in Amazon S3, not for scanning Lambda function code for vulnerabilities.

C. Use GuardDuty and Security Hub.

GuardDuty is a threat detection service, and Security Hub aggregates security findings. Neither service performs static code analysis or scans Lambda functions for code vulnerabilities.

D. Use GuardDuty Lambda Protection.

This GuardDuty feature detects runtime threats and anomalous behavior in Lambda functions, such as malicious invocations, but it does not scan the function's code for vulnerabilities.

1. AWS Documentation: Amazon Inspector User Guide. "Scanning AWS Lambda functions with Amazon Inspector." This section states, "When you activate Lambda scanning, Amazon Inspector automatically discovers all of your Lambda functions... and immediately starts scanning them for vulnerabilities... Amazon Inspector scans Lambda functions for two types of vulnerabilities: Package vulnerabilities... [and] Code vulnerabilities."

2. AWS Documentation: Amazon Inspector User Guide. "Amazon Inspector scans for code vulnerabilities." This page details how Inspector uses automated reasoning and machine learning to detect code vulnerabilities in Lambda functions, covering categories like injection flaws and data leaks.

3. AWS Documentation: Amazon Macie User Guide. "What is Amazon Macie?" The first sentence clarifies its purpose: "Amazon Macie is a data security service that discovers sensitive data by using machine learning and pattern matching."

4. AWS Documentation: Amazon GuardDuty User Guide. "Lambda Protection in GuardDuty." This document explains, "GuardDuty Lambda Protection is a feature in Amazon GuardDuty that monitors AWS CloudTrail management events and VPC Flow Logs to detect threats against your Lambda functions." This confirms its focus is on runtime threat detection, not static code scanning.

AWS Config is the primary service for assessing, auditing, and evaluating the configurations of AWS resources. It continuously monitors and records your AWS resource configurations and allows you to automate the evaluation of recorded configurations against desired configurations. For this scenario, AWS Config provides managed rules that can specifically check Amazon Aurora instances for compliance with the stated security requirements. These rules include checks for public accessibility (rds-instance-public-access-check), storage encryption (rds-storage-encrypted), deletion protection (rds-instance-deletion-protection-enabled), and log exports (aurora-mysql-log-exports-enabled), providing the required continuous monitoring and real-time visibility into the compliance status.

A. Use AWS Audit Manager with a custom framework.

AWS Audit Manager is designed for collecting evidence for audits, not for real-time configuration monitoring and alerting. It often uses AWS Config as an evidence source.

C. Use AWS Security Hub configuration policies.

AWS Security Hub aggregates security findings and uses AWS Config rules for many of its checks. AWS Config is the foundational service that performs the actual configuration evaluation.

D. Use EventBridge and Lambda with custom metrics.

This is a custom-built solution that requires significant development and maintenance effort, whereas AWS Config provides a managed, out-of-the-box solution for this exact purpose.

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1. AWS Config Documentation - rds-storage-encrypted: "Checks whether storage encryption is enabled for your Amazon Relational Database Service (Amazon RDS) DB instances."

Source: AWS Config Developer Guide, "List of AWS Config Managed Rules", rds-storage-encrypted.

2. AWS Config Documentation - rds-instance-deletion-protection-enabled: "Checks if an Amazon Relational Database Service (Amazon RDS) instance has deletion protection enabled."

Source: AWS Config Developer Guide, "List of AWS Config Managed Rules", rds-instance-deletion-protection-enabled.

3. AWS Config Documentation - rds-instance-public-access-check: "Checks whether the Amazon Relational Database Service (RDS) instances are not publicly accessible."

Source: AWS Config Developer Guide, "List of AWS Config Managed Rules", rds-instance-public-access-check.

4. AWS Config Documentation - aurora-mysql-log-exports-enabled: "Checks if an Amazon Aurora MySQL DB cluster has the specified log types exported to Amazon CloudWatch Logs." (The specified log types can include 'audit').

Source: AWS Config Developer Guide, "List of AWS Config Managed Rules", aurora-mysql-log-exports-enabled.

5. AWS Config Documentation - What Is AWS Config?: "AWS Config is a service that enables you to assess, audit, and evaluate the configurations of your AWS resources. Config continuously monitors and records your AWS resource configurations and allows you to automate the evaluation of recorded configurations against desired configurations."

Source: AWS Config Developer Guide, "What Is AWS Config?".