SCS-C02 Practice Test 8 — 10 Questions

Question 1

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 2

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 3

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 4

A company needs to grant cross-account access to an S3 bucket. Which IAM feature should be used?

Accepted Answer

Use an S3 bucket policy that grants access to the external account's IAM users.. A bucket policy can grant access to principals in another account. Option A is wrong because IAM users are within the same account. Option C is wrong because SCPs apply within an organization. Option D is wrong because a role can be used but requires the external account to assume the role, not directly access the bucket.

Answer

Create an IAM user in the source account and share the credentials.

Answer

Use a service control policy (SCP) to allow cross-account access.

Answer

Use an IAM role in the source account that the external account can assume.

Question 5

An organization wants to enforce that all IAM users must use MFA to access the AWS API. Which TWO steps should be taken?

Accepted Answer

Attach the policy to all IAM users or to a group that all users belong to.. Options B and C are correct. An IAM policy with a condition that denies access if MFA is not present (C) must be attached to all users or groups (B). Option A is wrong because rotating access keys does not enforce MFA. Option D is wrong because password policy only affects console login. Option E is wrong because SCPs cannot enforce MFA for IAM users in the same account; they apply to member accounts.

Answer

Rotate all IAM user access keys.

Answer

Configure the account password policy to require MFA.

Answer

Create a service control policy (SCP) that requires MFA for all API calls.

Question 6

A security engineer is investigating a potential data exfiltration incident. They suspect that an EC2 instance was compromised and used to transfer large amounts of data from an S3 bucket to an external IP address. The engineer has enabled VPC Flow Logs for the subnet where the EC2 instance resides, but the logs are not capturing traffic to the external IP. What is the most likely reason?

Accepted Answer

The traffic is routed through a NAT gateway, and flow logs are not enabled on the NAT gateway's subnet.. VPC Flow Logs capture traffic at the subnet or ENI level. If traffic from an EC2 instance to an external IP is routed through a NAT gateway, the flow logs on the EC2 instance's subnet will only show traffic to the NAT gateway, not the external IP. To capture the external traffic, flow logs must be enabled on the subnet where the NAT gateway resides. Option A is incorrect because Security Groups do not affect flow log capture; they filter traffic but flow logs log both accepted and rejected traffic. Option B is incorrect because VPC Flow Logs capture all traffic, not just rejected. Option C is incorrect because flow logs capture traffic to any IP, not just other VPC resources.

Answer

The EC2 instance's security group is blocking the traffic.

Answer

VPC Flow Logs only capture rejected traffic.

Answer

VPC Flow Logs only capture traffic to and from other VPC resources.

Question 7

A company wants to protect data stored in Amazon S3 by encrypting it at rest using keys managed by the company. Which encryption option should be used?

Accepted Answer

SSE-C. (SSE-KMS) is incorrect because while the customer can manage KMS keys, they are stored and managed by AWS KMS, not directly provided by the customer. The question specifies the company manages the keys themselves. Option B (SSE-C) is correct because it allows the customer to provide their own encryption keys and manage them outside AWS. Option C (client-side encryption) is incorrect because it encrypts data before upload, not at rest in S3. Option D (SSE-S3) is incorrect because it uses AWS-managed keys, not customer-managed keys.

Answer

SSE-KMS

Answer

Client-side encryption

Answer

SSE-S3

Question 8

A security engineer is configuring Amazon Inspector to assess EC2 instances for software vulnerabilities. The engineer has installed the SSM Agent on all instances and ensured that the instances have internet access. However, Amazon Inspector shows the instances as 'Unmanaged'. What is the MOST likely cause?

Accepted Answer

The SSM Agent is not running or is not registered with AWS Systems Manager.. Amazon Inspector requires EC2 instances to be managed by AWS Systems Manager (SSM) to install the SSM Agent and register it with the Systems Manager service. If the SSM Agent is not running or not registered, the instance cannot communicate with Systems Manager, and Inspector will report it as 'Unmanaged'. Even with internet access and the agent installed, the agent must be actively running and registered for the instance to be properly managed.

Answer

The IAM role attached to the EC2 instance does not have permissions to publish metrics to CloudWatch.

Answer

The security group attached to the instance blocks outbound traffic to the Amazon Inspector service.

Answer

The instance does not have the EC2 instance metadata service enabled.

Question 9

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 10

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