Free Amazon Web Services SCS-C03 Practice Exam with Questions & Answers | Set: 3

Amazon S3 Block Public Access provides centralized controls to prevent public access through bucket policies and ACLs. AWS Certified Security – Specialty guidance recommends enabling Block Public Access to reduce accidental exposure and to enforce guardrails that override public grants. Enabling Block Public Access on the bucket removes current public exposure when combined with correcting policies/ACLs and prevents future misconfiguration. To ensure the bucket cannot be made public again, the security engineer must prevent principals from disabling Block Public Access. An SCP that denies s3:PutPublicAccessBlock prevents changes that would remove or weaken the PublicAccessBlock configuration, enforcing the guardrail across the OU or account. Options A and D do not directly address public exposure control. Option B denies object reads but does not ensure public access cannot be re-enabled; it also does not address the root misconfiguration pathways and could disrupt legitimate access patterns. Option C specifically combines the correct preventive control (PublicAccessBlock) with organizational enforcement to stop future reversal.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon S3 Block Public Access

AWS Organizations SCP Guardrails for S3 Controls

To keep S3 accessoff the public internet, the standard AWS approach is to use anAmazon S3 gateway VPC endpoint(AWS PrivateLink for S3 is not used; S3 uses gateway endpoints). A gateway endpoint adds routes in the VPC route tables so traffic destined for S3 stays on the AWS backbone network rather than traversing an internet gateway, NAT gateway, or public IP paths. This satisfies the “cannot send traffic over the public internet” requirement while allowing the application in Account A to reach S3 in the same Region.

Cross-account bucket access is controlled byIAM and the S3 bucket policy, not by networking between the two accounts’ VPCs. The bucket resides in S3 (a regional service), not inside Account B’s VPC, so connecting VPC-to-VPC (peering, transit gateway, VPN) does not inherently provide private access to S3. Those options would add complexity and still typically require internet/NAT unless S3 endpoints are used.

With the gateway endpoint in Account A, the application can privately reach S3, and because permissions are already granted to write to the bucket in Account B, the write operations will succeed without public internet routing.

Comprehensive and Detailed 100to 150 words of Explanation From AWS Certified Security – Specialty topics:

AWS CloudFormation Guard is the correct policy-as-code control for validating CloudFormation templates before deployment. Guard lets security teams write rules that check JSON or YAML templates for policy requirements, such as requiring encrypted EBS volumes. AWS CloudFormation best practices specifically recommend integrating cfn-guard into CI/CD pipelines to validate templates before deployment and prevent noncompliant resources from reaching the environment. AWS Config is mainly detective or proactive compliance evaluation after or during resource provisioning, but the question asks to prevent deployment inside an IaC pipeline. Trusted Advisor does not validate templates. SCPs restrict account-level permissions but are not a CloudFormation template validation engine.

================

Amazon SQS is an AWS-managed service and does not operate within customer VPCs. Therefore, security groups and network ACLs cannot be used to control access to SQS, making options A and B invalid. According to AWS Certified Security – Specialty documentation, the recommended approach to securely access AWS services from within a VPC is throughinterface VPC endpoints (AWS PrivateLink).

By creatinginterface VPC endpoints for Amazon SQS, the company ensures that traffic to SQS stays within the AWS network and does not traverse the public internet. Adding anSQS resource policywith the aws:SourceVpce condition restricts access so that only requests originating from the specified VPC endpoint are allowed. Additionally, using the aws:PrincipalOrgId condition ensures that only principals belonging to the same AWS Organization can access the queue.

Option D introduces an external tool, increasing cost and compliance complexity, which directly violates the requirement to minimize investment outside AWS.

AWS documentation clearly identifiesVPC endpoints combined with IAM condition keysas a best practice for securing service access in multi-account environments.

AWS Certified Security – Specialty Official Study Guide

Amazon SQS Security Best Practices

AWS Organizations Documentation

AWS PrivateLink User Guide

Amazon Macie is the AWS service designed specifically to discover, classify, and report sensitive data stored in Amazon S3. According to the AWS Certified Security – Specialty Study Guide, Macie uses machine learning and managed data identifiers to automatically detect sensitive data types such as PII and financial information.

Macie integrates natively with Amazon EventBridge, allowing findings to be routed to other services such as Amazon SNS with minimal configuration. Creating an EventBridge rule to forward Macie findings to an existing SNS topic satisfies the notification requirement without custom code.

Option A is invalid because AWS Config does not inspect object contents. Option B requires custom development and ongoing maintenance. Option D is incorrect because Amazon GuardDuty focuses on threat detection, not sensitive data discovery.

AWS documentation emphasizes Macie as the lowest-effort and most accurate solution for sensitive data identification in S3.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon Macie Sensitive Data Discovery

Amazon EventBridge Integration with Security Services

Comprehensive and Detailed 100to 150 words of Explanation From AWS Certified Security – Specialty topics:

DNSSEC validation depends on a chain of trust from the parent zone to the signed child zone. After enabling DNSSEC signing and creating a KSK for the subdomain, the parent zone must contain a Delegation Signer (DS) record that points to the child zone’s DNSSEC key material. Without the DS record in the parent, validating resolvers cannot establish the trust chain, so the configuration appears broken. The DS record does not belong in the subdomain zone itself for this trust-linking purpose. Replacing the KSK with a ZSK is conceptually wrong because the KSK is the key associated with the DS record chain. Reactivating the KSK does not fix a missing parent-zone delegation signer record.

================

Step 1:Obtain the SAML metadata fromIAM Identity Center.

Step 2:Obtain the SAML metadata from theexternal IdP.

Step 3:Configure theexternal IdP as the identity sourceinIAM Identity Center.

When integratingAWS IAM Identity Center (formerly AWS SSO)with anexternal identity provider (IdP)usingSAML 2.0, AWS requires a specific sequence of steps to establish trust and federation correctly.

Step 1: Obtain the SAML metadata from IAM Identity Center

IAM Identity Center acts as theservice provider (SP)in the SAML trust. The external IdP must trust IAM Identity Center, so the IdP needs IAM Identity Center’s SAML metadata first. This metadata contains critical information such as the SP entity ID, ACS (Assertion Consumer Service) URL, and signing certificate. Without this metadata, the external IdP cannot be configured to send assertions to AWS.

Step 2: Obtain the SAML metadata from the external IdP

After the external IdP is configured to trust IAM Identity Center, the IdP generates its own SAML metadata. This metadata includes the IdP entity ID, SSO endpoint, and signing certificate. IAM Identity Center requires this information to validate authentication assertions coming from the external IdP.

Step 3: Configure the external IdP as the identity source in IAM Identity Center

Once both metadata files are available, the security engineer configures the external IdP as theidentity sourcein IAM Identity Center. At this stage, IAM Identity Center imports the IdP metadata and establishes the SAML trust relationship. After this configuration, users authenticated by the external IdP can be federated into AWS accounts and applications via IAM Identity Center.

Why the other options are incorrect:

Creating an IAM role with an IdP API endpoint is used forIAM federation, not IAM Identity Center.

Automatic provisioning (SCIM) is optional and is configuredafterSAML federation is established.

Automatic provisioning must be enabled onboth sides, but it is not required to complete the core IdP integration.

This sequence follows AWS best practices for SAML-based federation with IAM Identity Center.

Comprehensive and Detailed 100to 150 words of Explanation From AWS Certified Security – Specialty topics:

Secrets Manager is the appropriate service for database credentials because it encrypts secrets at rest with AWS KMS and retrieves them over TLS. The application should stop storing sensitive credentials directly in environment variables and retrieve them from Secrets Manager at runtime, or the ECS task should reference the secret securely through the task definition. In either design, the task role or task execution role must have permission to call secretsmanager:GetSecretValue and kms:Decrypt for the specific secret and KMS key. Storing credentials in S3 is a weaker secret-management pattern. A Fargate task has no EC2 container instance role that the customer manages. Logging in to a Fargate instance is not valid and would not be an auditable secure deployment pattern

Amazon GuardDuty generates security findings when it detects suspicious or malicious activity, includingCryptoCurrency:EC2/* findings that indicate an EC2 instance may be involved in unauthorized cryptocurrency mining. According to AWS Certified Security – Specialty documentation, GuardDuty findings are published as events toAmazon EventBridge(formerly Amazon CloudWatch Events).

Amazon EventBridge is the recommended service for buildingautomated incident response workflows. By creating an EventBridge rule that listens for GuardDuty findings of type CryptoCurrency:EC2/*, the security engineer can automatically invoke a Lambda function to isolate the affected EC2 instance by modifying its security group attachments.

Option A is incorrect because GuardDuty does not directly invoke Lambda functions. Option B and Option D are incorrect because AWS Config tracks configuration compliance and resource changes, not real-time threat detection events. Cryptocurrency findings are security detections, not configuration changes.

AWS documentation explicitly describes this pattern—GuardDuty → EventBridge → Lambda → remediation action—as a best practice for automated threat response and containment.

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty User Guide – Findings

Amazon EventBridge User Guide

AWS Incident Response Best Practices

AWS Config is a fully managed service that providescontinuous monitoring and evaluation of AWS resource configurationsagainst desired configuration baselines. According to the AWS Certified Security – Specialty Official Study Guide, AWS Config is the primary service used totrack configuration changes, evaluate compliance in near real time, and display compliance statesfor individual AWS resources.

AWS Config providesmanaged rulesthat directly map to the listed Aurora MySQL security requirements, including encryption at rest, public accessibility, deletion protection, and log exports to CloudWatch Logs. These managed rules continuously evaluate resources and mark them as compliant or noncompliant whenever a configuration change occurs.

The AWS Config dashboard enables security engineers to viewper-resource and per-rule compliance states at any point in time, satisfying the requirement to display compliance status for each part of the policy.

AWS Audit Manager (Option A) is designed for audit evidence collection and reporting, not continuous monitoring. AWS Security Hub (Option C) aggregates findings from other services but relies on AWS Config for configuration compliance data. Option D introduces unnecessary custom logic and does not provide a native compliance dashboard.

AWS documentation explicitly identifiesAWS Config as the authoritative service for continuous compliance monitoring and visibility.

AWS Certified Security – Specialty Official Study Guide

AWS Config Developer Guide

Amazon Aurora Security Best Practices

AWS Well-Architected Framework – Security Pillar