SCS-C02 Practice Test 3 — 10 Questions

Question 1

A company wants to encrypt data at rest in Amazon S3 using server-side encryption with Amazon S3-managed keys (SSE-S3). What is the minimum permission required for an IAM user to upload an object that will be encrypted with SSE-S3?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

s3:PutObject. (s3:PutObject) is correct. SSE-S3 does not require any special permissions beyond s3:PutObject; S3 handles the encryption automatically. Option A (s3:PutObjectAcl) is wrong because it is for managing object ACLs, not for uploading. Option B (kms:Decrypt) is wrong because it is not needed for SSE-S3; kms:Decrypt is used for decryption with KMS. Option D (kms:GenerateDataKey) is wrong because it is needed for SSE-KMS, not SSE-S3.

Answer

s3:PutObjectAcl

Answer

kms:Decrypt

Answer

kms:GenerateDataKey

Question 2

A company is designing a data protection strategy for Amazon EFS file systems. The security team requires encryption at rest and in transit. Additionally, the team needs to control which KMS keys can be used to encrypt the file system. Which THREE steps should the team take?

Accepted Answer

Configure a KMS key policy that allows the EFS service to use the key.. You must configure the KMS key policy to allow the EFS service to use the key for encryption at rest. Option B is correct because encryption at rest is enabled by specifying a customer-managed KMS key when creating the EFS file system. Option E is correct because encryption in transit is enabled by using the TLS option when mounting the file system on the client. Option C is incorrect because EFS does not support SSE-S3; it uses KMS for encryption at rest. Option D is incorrect because IAM policies can restrict who can create encrypted file systems, but the question specifically asks about controlling which KMS keys can be used, which is done via KMS key policies, not IAM policies.

Answer

Enable default encryption on the EFS file system using SSE-S3.

Answer

Use an IAM policy to restrict which users can create encrypted file systems.

Question 3

A security engineer is troubleshooting an issue where an EC2 instance cannot access an S3 bucket via a VPC endpoint. The bucket policy allows access only from the VPC endpoint. The instance has an IAM role that grants s3:GetObject on the bucket. The EC2 instance receives an AccessDenied error. What is the most likely cause?

Accepted Answer

The bucket policy does not include the aws:SourceVpce condition.. The AccessDenied error occurs because the S3 bucket policy must include the aws:SourceVpce condition to allow access from the specific VPC endpoint. Without this condition, the bucket policy denies all requests that do not originate from the endpoint, regardless of IAM permissions. Option B is correct because the missing condition is the most likely cause.

Answer

The IAM role does not have sufficient permissions.

Answer

The VPC endpoint policy is blocking the request.

Answer

The EC2 instance's security group does not allow outbound traffic to S3.

Question 4

A company is using AWS Organizations to manage multiple accounts. The security team wants to prevent the creation of Amazon EC2 instances with public IP addresses in all accounts. Which TWO actions should the team take to implement this control using Service Control Policies (SCPs)?

Accepted Answer

Create an SCP with a Deny effect for ec2:RunInstances where the request parameter ec2:AssociatePublicIpAddress is true.. An SCP with a Deny effect for ec2:RunInstances can use the condition key ec2:AssociatePublicIpAddress to block instance creation when a public IP is requested. Option D is correct because attaching the SCP to the root OU ensures it applies to all accounts in the organization. Option A is wrong because the condition key ec2:LaunchTemplate is used to restrict based on launch templates, not public IP assignment. Option B is wrong because SCPs do not add IAM policies; they set permission boundaries that deny or allow actions. Option E is wrong because SCPs can deny actions based on tags but the condition key for public IP is ec2:AssociatePublicIpAddress, not a tag.

Answer

Use the condition key 'ec2:LaunchTemplate' to deny public IPs.

Answer

Create an SCP that adds an IAM policy to deny ec2:RunInstances.

Answer

Create an SCP that requires the tag 'PublicIP' to be set to 'false'.

Question 5

A company has a VPC with public and private subnets. The private subnets need to access the internet for software updates. Which component should be added to the VPC to enable this?

Accepted Answer

NAT gateway. (NAT gateway). A NAT gateway enables instances in a private subnet to initiate outbound traffic to the internet for tasks like software updates, while preventing inbound traffic from the internet. Option A (Internet gateway) is incorrect because it is used for public subnets to allow direct internet access. Option B (VPN connection) is used for secure connectivity to an on-premises network, not for outbound internet access. Option C (VPC peering connection) is used to connect two VPCs, not to provide internet access.

Answer

Internet gateway

Answer

VPN connection

Answer

VPC peering connection

Question 6

A security engineer is investigating a potential data exfiltration incident. The engineer notices large volumes of data being transferred from an Amazon S3 bucket to an external IP address. Which AWS services can be used to detect and alert on such behavior? (Choose THREE.)

Accepted Answer

Amazon CloudWatch Logs with S3 access log analysis.. Amazon CloudWatch Logs can ingest and analyze S3 access logs, which record detailed information about requests made to an S3 bucket, including the source IP address, request type, and bytes transferred. By analyzing these logs with CloudWatch Logs Insights or metric filters, you can detect large data transfers to external IPs and trigger alerts via CloudWatch Alarms, making it a valid detection and alerting mechanism for data exfiltration.

Answer

AWS Config with compliance rules.

Answer

VPC Flow Logs.

Question 7

A security engineer is designing a VPC with a public subnet and a private subnet. The private subnet will host a database instance that should only be accessible from the application instances in the public subnet. The application instances use an Auto Scaling group. Which configuration ensures that only the application instances can access the database?

Accepted Answer

Allow inbound database port from the security group attached to the application instances in the public subnet.. Security group rules can reference other security groups, allowing dynamic scaling of the application instances without needing to update CIDR blocks. Auto Scaling group instances are automatically assigned the application security group, so only they can access the database. Option B is incorrect because allowing 0.0.0.0/0 would expose the database to the internet. Option C is incorrect because network ACLs are stateless and cannot reference security groups; they would require explicit rules for return traffic. Option D is incorrect because referencing the public subnet CIDR would allow any instance in that subnet, not just the application instances, and would not handle changes in the application instances' IPs.

Answer

Allow inbound database port from 0.0.0.0/0 in the database security group.

Answer

Configure a network ACL on the private subnet to allow the database port from the public subnet CIDR.

Answer

Allow inbound database port from the public subnet CIDR block in the database security group.

Question 8

A Security Engineer is configuring a VPC with a public subnet for a web server and a private subnet for a database. The web server needs to download patches from the internet. Which TWO actions should the Engineer take to allow the web server internet access without exposing the database to the internet?

Accepted Answer

Create a NAT Gateway in the public subnet.. A NAT Gateway in the public subnet allows instances in the private subnet to initiate outbound IPv4 traffic to the internet (e.g., to download patches) while preventing unsolicited inbound connections from the internet. By adding a route in the private subnet's route table that points 0.0.0.0/0 to the NAT Gateway, the web server's outbound traffic is forwarded to the NAT Gateway, which then uses the Internet Gateway to reach the internet. The database remains isolated because it has no direct route to the Internet Gateway and no public IP address.

Answer

Create a bastion host in the public subnet and configure the web server to use it as a proxy.

Answer

Create a VPC endpoint for Amazon S3.

Answer

Attach an Internet Gateway to the VPC and add a route to the Internet Gateway in the private subnet's route table.

Question 9

Which TWO actions can be taken to protect an S3 bucket from accidental public access? (Choose 2.)

Accepted Answer

Enable S3 Block Public Access at the account level. Options A and B are correct. Enabling S3 Block Public Access at the account level (option A) prevents any public access to all buckets. Using a bucket policy with a condition that denies s3:PutBucketPolicy unless the request comes from a specific VPC (option B) ensures that only authorized VPCs can modify the bucket policy, preventing accidental public exposure. Option C is wrong because default encryption does not affect public access. Option D is wrong because MFA Delete protects against accidental deletion, not public access. Option E is wrong because requiring MFA for S3 actions does not prevent public access.

Answer

Enable default encryption for the bucket

Answer

Enable MFA Delete on the bucket

Answer

Use an IAM policy that requires MFA for all S3 actions

Question 10

A security engineer is designing a web application that will run on EC2 instances behind an Application Load Balancer (ALB). The application must be protected from common web exploits like SQL injection and cross-site scripting. Which AWS service should be used to provide this protection?

Accepted Answer

AWS WAF. AWS WAF is a web application firewall that helps protect web applications from common web exploits like SQL injection and cross-site scripting. Network ACLs are stateless firewalls at the subnet level and do not inspect application-layer traffic. Security Groups are stateful firewalls at the instance level and do not provide application-layer filtering. AWS Shield Advanced provides DDoS protection, not application-layer attack prevention.

Answer

Network ACLs

Answer

Security Groups

Answer

AWS Shield Advanced