SCS-C02 Practice Test 1 — 25 Questions

Question 1

A company uses AWS Organizations with multiple accounts. The security team wants to enforce that all Amazon S3 buckets across the organization have server-side encryption (SSE-S3 or SSE-KMS) enabled. Which approach should be used to enforce this policy?

Accepted Answer

Create a service control policy (SCP) that denies s3:CreateBucket if the bucket does not have encryption enabled.. Option D is correct because Service Control Policies (SCPs) in AWS Organizations allow you to centrally deny API actions across all accounts. By creating an SCP that denies `s3:CreateBucket` unless the request includes encryption parameters (SSE-S3 or SSE-KMS), you enforce encryption at the point of bucket creation, preventing non-compliant buckets from ever being created. This is the only approach that proactively enforces the policy across the entire organization, rather than relying on detection or per-account configurations.

Answer

Create an S3 bucket policy in each account to deny access to unencrypted buckets.

Answer

Use AWS Config rules to detect buckets without encryption and send alerts.

Answer

Create an IAM role in each account that requires encryption when creating buckets.

Question 2

A company is designing a multi-tier web application on AWS. The web tier must be accessible from the internet, but the application and database tiers must be isolated. The security team requires that all traffic between tiers be encrypted and that the application tier can only be accessed by the web tier. Which architecture should be used?

Accepted Answer

Place the web tier in a public subnet with an internet gateway, and the app and database tiers in private subnets. Use separate security groups for each tier, allowing only necessary traffic.. Option B is correct because it places the web tier in a public subnet with an Internet Gateway (IGW) for internet-facing access, while the application and database tiers reside in private subnets with no direct internet path. Separate security groups enforce least-privilege: the web tier security group allows inbound HTTP/HTTPS (ports 80/443) from 0.0.0.0/0, the app tier security group allows inbound traffic only from the web tier security group (using a security group reference), and the database tier security group allows inbound traffic only from the app tier security group. This ensures encryption (e.g., TLS for web-to-app, and database-native encryption like TLS or AWS RDS encryption in transit) and complete isolation of the internal tiers.

Answer

Place all tiers in public subnets and use security groups to restrict traffic.

Answer

Place the web and app tiers in public subnets and the database in a private subnet.

Answer

Place all tiers in private subnets and use a single security group to allow traffic between them.

Question 3

A company is migrating a legacy application to AWS. The application requires two-way communication between the web servers and the database servers using TCP port 3306. The security team wants to follow the principle of least privilege. Which TWO actions should be taken to secure the traffic?

Accepted Answer

Create a security group for the web servers that allows outbound traffic on port 3306 to the database security group.. Option A is correct because security groups are stateful, so allowing outbound traffic on port 3306 from the web servers to the database security group automatically permits the corresponding return traffic. This adheres to the principle of least privilege by specifying the destination as the database security group ID rather than a broad CIDR range, ensuring only the intended web servers can initiate the connection.

Answer

Create a security group for the database servers that allows inbound traffic on port 3306 from the web subnet CIDR.

Answer

Place the database servers in a public subnet for easier connectivity.

Answer

Configure the network ACL for the database subnet to allow inbound traffic on port 3306 from the web subnet CIDR.

Question 4

A security engineer is troubleshooting connectivity issues between an Amazon EC2 instance in a VPC and an on-premises server over a Direct Connect virtual interface. The EC2 instance has a security group that allows outbound traffic to the on-premises CIDR block (10.0.0.0/16). The VPC has a route table entry pointing the on-premises CIDR to the virtual private gateway. The on-premises firewall shows that packets are received from the EC2 instance but responses are not reaching the instance. What is the most likely cause?

Accepted Answer

The on-premises router does not have a route pointing the VPC CIDR back to the Direct Connect interface.. The on-premises firewall logs show packets are received from the EC2 instance, but responses are not reaching it. This indicates a routing issue on the on-premises side: the on-premises router must have a route pointing the VPC CIDR back to the Direct Connect interface (virtual interface) for return traffic to be forwarded correctly. Without this return route, the on-premises server sends responses via its default route (likely the internet), which are dropped by the VPC security group or never reach the EC2 instance.

Answer

The network ACL for the subnet is blocking outbound traffic to the on-premises CIDR.

Answer

The virtual private gateway is not attached to the VPC.

Answer

The security group does not allow inbound traffic from the on-premises server.

Question 5

A security engineer is reviewing the SQS queue policy shown in the exhibit. The queue is subscribed to an SNS topic in the same account. The security team has a requirement that only the SNS topic should be allowed to send messages to the queue. What is the issue with this policy?

Accepted Answer

The second statement allows any principal in the 10.0.0.0/8 range to receive messages from the queue.. Option A is correct because the second statement in the SQS queue policy allows any principal in the 10.0.0.0/8 IP range to receive messages from the queue, which violates the security requirement that only the SNS topic should be allowed to send messages. The policy should restrict the `sqs:SendMessage` action to the SNS topic using a condition like `aws:SourceArn` and should not include a broad `Effect: Allow` for `sqs:ReceiveMessage` without restricting the principal or source.

Answer

The policy does not specify a principal, so it will not work.

Answer

The aws:SourceArn condition uses ArnLike which is deprecated.

Answer

The aws:SourceIp condition cannot be used with SQS queue policies.

Question 6

A company uses AWS Organizations with multiple accounts. The security team wants to ensure that all IAM users in the production account must use multi-factor authentication (MFA) to access the AWS Management Console. Which combination of actions should the security team take to enforce this requirement?

Accepted Answer

Create an IAM policy that denies all console actions unless MFA is present. Attach the policy to the IAM group that contains all production users.. Option D is correct because an IAM policy with a condition that denies all console actions unless MFA is present can be attached to an IAM group containing all production users. This enforces MFA at the user level within the account, directly meeting the requirement to ensure all IAM users in the production account must use MFA to access the AWS Management Console.

Answer

Use an SCP to deny access to the AWS Management Console unless MFA is present. Attach the SCP to the production OU.

Answer

Disable password-based access for all IAM users and require federation with an identity provider that enforces MFA.

Answer

Enable MFA on the root user and apply a password policy that requires MFA.

Question 7

A developer is trying to upload an object to an S3 bucket named 'my-bucket' using the AWS CLI. The developer has an IAM user with a policy that includes 's3:PutObject' for 'arn:aws:s3:::my-bucket/*'. However, the upload fails with an 'Access Denied' error. The bucket policy is set to allow all principals from the same AWS account to perform 's3:PutObject'. What is the most likely cause of this failure?

Accepted Answer

The IAM policy grants 's3:PutObject' only on objects (/*), but the request may also require 's3:PutObject' on the bucket itself for some operations.. Option C is correct because the IAM policy grants 's3:PutObject' only on the bucket's object ARN (arn:aws:s3:::my-bucket/*), but certain S3 operations, such as multipart uploads initiated via the AWS CLI, may require the 's3:PutObject' permission on the bucket resource itself (arn:aws:s3:::my-bucket) to complete the upload. The bucket policy allows 's3:PutObject' for all principals in the same account, but the IAM user's policy is too restrictive, causing the 'Access Denied' error.

Answer

The IAM user is not authorized to perform 's3:PutObject' on the bucket 'my-bucket'.

Answer

The bucket policy denies access because the principal is not explicitly listed.

Answer

The bucket 'my-bucket' does not exist in the same region as the CLI request.

Question 8

A security administrator is designing a cross-account access strategy. The administrator needs to allow users in Account A to assume an IAM role in Account B to access an S3 bucket. Which TWO of the following statements are true regarding this configuration?

Accepted Answer

The IAM users in Account A must have an IAM policy that allows the sts:AssumeRole action for the role ARN in Account B.. Option A is correct because for an IAM user in Account A to assume a role in Account B, the user must be explicitly granted permission to call the sts:AssumeRole API action against the role's Amazon Resource Name (ARN). This is done by attaching an IAM policy to the user (or a group/role the user belongs to) that includes the sts:AssumeRole action and specifies the target role ARN as the resource. Without this permission, the user cannot initiate the cross-account role assumption, even if the role's trust policy allows it.

Answer

The trust policy for the role must be defined in Account A.

Answer

The S3 bucket policy must grant access to the IAM users in Account A.

Answer

The IAM users in Account A must have cross-account permissions on the S3 bucket in Account B.

Question 9

An IAM policy is attached to a user. The user is trying to change their own password in the IAM console but receives an 'Access Denied' error. The user has an MFA device configured and is logged in with MFA. Why is the password change failing?

Accepted Answer

The Deny statement uses 'BoolIfExists' which evaluates to true if the condition key is not present. In the IAM console, the 'aws:MultiFactorAuthPresent' key may not be set, causing the Deny to apply even when the user has MFA.. Option B is correct because the Deny statement uses the `BoolIfExists` condition operator with the `aws:MultiFactorAuthPresent` key. In the IAM console, the `aws:MultiFactorAuthPresent` key may not be present in the request context (e.g., during the initial password change flow before MFA is re-validated), causing `BoolIfExists` to evaluate to true when the key is absent. This triggers the Deny even though the user has an MFA device and is logged in with MFA, blocking the `iam:ChangePassword` action.

Answer

The Allow statement for iam:ChangePassword is not sufficient because the Deny statement explicitly denies all actions.

Answer

The Deny statement denies all actions unconditionally, so the Allow statement cannot override it.

Answer

The user does not have permission to change their own password because the Allow statement is not specific enough.

Question 10

A Security Engineer needs to block SSH traffic (port 22) from the internet to all EC2 instances in a VPC. Which approach is the most secure and scalable?

Accepted Answer

Add a network ACL rule to deny inbound traffic on port 22 from 0.0.0.0/0 at the subnet level.. Option B is correct because network ACLs (NACLs) are stateless and operate at the subnet level, allowing you to explicitly deny inbound SSH traffic from 0.0.0.0/0. This approach is more secure and scalable than security group rules because NACLs can block traffic before it reaches the instance, and they support explicit deny rules, which security groups do not. Security groups only support allow rules, so you cannot add a deny rule to block SSH traffic; you must omit the allow rule, which is less explicit and can be accidentally overridden.

Answer

Add a security group rule to deny inbound traffic on port 22 from 0.0.0.0/0.

Answer

Add a network ACL rule to allow inbound traffic on port 22 from 0.0.0.0/0 and then add a deny rule for the same traffic.

Answer

Add a security group rule to block inbound traffic on port 22 from 0.0.0.0/0 at the VPC level.

Question 11

A security engineer is reviewing a CloudTrail log entry (exhibit). What is the most immediate security concern indicated by this event?

Accepted Answer

A security group rule was added allowing SSH access from any IP address.. The CloudTrail log shows an AuthorizeSecurityGroupIngress API call that added a security group rule with the CIDR 0.0.0.0/0 for port 22 (SSH). This effectively opens SSH access to the entire internet, creating a severe exposure that could allow any attacker to attempt brute-force or credential-stuffing attacks against any EC2 instance associated with that security group. This is the most immediate security concern because it directly introduces a wide-open attack surface.

Answer

The source IP address 203.0.113.5 is from a known malicious IP range.

Answer

The API call was made from the AWS CLI, which may indicate a compromised access key.

Answer

The user JohnDoe did not use multi-factor authentication (MFA) for this API call.

Question 12

A startup is building a web application on AWS and needs to protect sensitive customer data at rest in an Amazon RDS for MySQL database. The compliance team requires that the encryption keys be managed by the company's on-premises hardware security module (HSM) and be rotated every 6 months. Which solution should the startup use?

Accepted Answer

Use AWS CloudHSM to store the encryption keys and enable RDS encryption with CloudHSM.. AWS CloudHSM provides a dedicated hardware security module (HSM) that allows you to manage encryption keys on-premises-style, meeting the requirement for key management on the company's own HSM. When you enable Amazon RDS for MySQL encryption with CloudHSM, the database encryption keys are stored and managed in the CloudHSM cluster, and you can rotate them every 6 months as required. This solution directly satisfies the compliance team's mandate for on-premises HSM key management and periodic rotation.

Answer

Use AWS KMS with a customer master key (CMK) and import key material from the on-premises HSM.

Answer

Store the encryption keys in AWS Secrets Manager and use them to encrypt the database.

Answer

Use AWS KMS with a custom key store backed by AWS CloudHSM.

Question 13

Which TWO of the following are valid methods to centrally manage security policies and enforce compliance across multiple AWS accounts? (Choose two.)

Accepted Answer

Deploy AWS Config conformance packs using AWS CloudFormation StackSets across accounts.. AWS Config conformance packs provide a way to deploy a collection of AWS Config rules and remediation actions across multiple accounts and Regions. When combined with AWS CloudFormation StackSets, you can centrally deploy these conformance packs to all accounts in an AWS Organization, ensuring consistent compliance enforcement. This approach allows you to define and manage security policies as code, automatically evaluating resources against desired configurations.

Answer

Attach IAM policies to all IAM users in each account.

Answer

Use AWS Security Hub to automatically enforce compliance rules.

Answer

Enable VPC Flow Logs in each account and send them to a central S3 bucket.

Question 14

Refer to the exhibit. An organization applies this SCP to an OU containing a developer account. A developer in that account tries to launch an m5.large instance using the AWS Management Console. What is the outcome?

Accepted Answer

The launch fails because the SCP denies RunInstances for instance types other than t2.micro and t2.small.. The SCP explicitly denies the ec2:RunInstances action when the condition key ec2:InstanceType does not match t2.micro or t2.small. Since m5.large is not in the allowed list, the deny effect applies, and the launch fails regardless of any IAM policy that might allow it. SCPs act as a guardrail that overrides IAM permissions, so even if the developer has full IAM access, the SCP blocks the operation.

Answer

The instance launches successfully because the SCP only applies to StartInstances, not RunInstances.

Answer

The instance launches successfully because the SCP does not explicitly allow any actions.

Answer

The launch fails only if the developer's IAM policy also denies the action.

Question 15

Which TWO are best practices for managing IAM roles for EC2 instances?

Accepted Answer

Apply the principle of least privilege when defining role permissions.. Option C is correct because the principle of least privilege ensures that an IAM role attached to an EC2 instance grants only the minimum permissions required for the application to function. This reduces the attack surface and limits potential damage from compromised instances. AWS Identity and Access Management (IAM) roles for EC2 use temporary security credentials obtained via the instance metadata service (IMDS), eliminating the need for long-term access keys.

Answer

Regularly rotate IAM user access keys.

Answer

Attach the same role to all instances for simplicity.

Answer

Store AWS access keys directly on the instance.

Question 16

A company wants to enforce encryption in transit for all traffic between its VPC and on-premises data center over AWS Direct Connect. Which TWO configurations can achieve this?

Accepted Answer

Use a public virtual interface with Direct Connect and configure an IPsec VPN over it.. Option A is correct because a public virtual interface over Direct Connect provides connectivity to public AWS endpoints, and by layering an IPsec VPN on top, you encrypt all traffic between your VPC and on-premises data center. This ensures encryption in transit while leveraging the low latency and reliability of Direct Connect. Option C is correct because a Direct Connect Gateway allows you to connect multiple VPCs to a Direct Connect private virtual interface, and configuring an IPsec VPN over that private virtual interface encrypts traffic end-to-end, meeting the encryption requirement.

Answer

Use a Site-to-Site VPN connection over the internet.

Answer

Use a Transit VPC architecture with VPN attachments.

Answer

Use a private virtual interface with Direct Connect.

Question 17

A company has multiple AWS accounts and wants to centralize VPC flow log analysis. Flow logs are enabled for all VPCs and are published to Amazon S3 buckets in each account. A security engineer needs to aggregate these logs into a single S3 bucket in the centralized logging account. What should the security engineer do?

Accepted Answer

Create an S3 bucket policy on the centralized bucket that allows the source accounts to write objects.. Option A is correct because an S3 bucket policy on the centralized logging account can grant the s3:PutObject permission to the source accounts' VPC flow log delivery service (or their root accounts), allowing them to write objects directly into the centralized bucket. This approach avoids data duplication, reduces costs, and simplifies management by eliminating the need for replication or streaming services.

Answer

Set up VPC peering between each account and the centralized logging account, then configure flow logs to write directly to the centralized bucket.

Answer

Configure S3 Replication between each account's flow log bucket and the centralized bucket.

Answer

Use Amazon CloudWatch Logs to stream flow logs to the centralized S3 bucket.

Question 18

A company is designing a shared services VPC architecture with multiple VPCs connected via a transit gateway. The security engineer needs to ensure that all traffic between VPCs is inspected by a centralized firewall appliance deployed in the shared services VPC. What configuration is required?

Accepted Answer

Configure transit gateway route tables to route all inter-VPC traffic through the firewall appliance.. Option B is correct because a transit gateway can use separate route tables to control traffic flow. By configuring the transit gateway route tables to point the default route (0.0.0.0/0) or specific inter-VPC CIDR ranges to a network interface of the centralized firewall appliance in the shared services VPC, all traffic between VPCs is forced through the firewall for inspection. This design ensures that the firewall acts as a central inspection point without requiring VPC peering or complex routing.

Answer

Create VPC peering connections between each VPC and the shared services VPC.

Answer

Use security groups to route traffic through the firewall.

Answer

Deploy a Gateway Load Balancer (GWLB) in the shared services VPC and register the firewall as a target.

Question 19

A company runs a web application on Amazon EC2 behind an Application Load Balancer (ALB). The application handles payment card information (PCI) and must comply with PCI DSS. The security team wants to ensure that all data in transit between the client and the ALB is encrypted using TLS 1.2 or higher. The ALB currently uses a default certificate from AWS Certificate Manager (ACM) that was issued by Amazon. The compliance team has flagged that the certificate must be issued by a public Certificate Authority (CA) that is trusted by major browsers. The company wants to minimize operational overhead. What should the security team do?

Accepted Answer

Request a public certificate from ACM and associate it with the ALB. Option D is correct. AWS Certificate Manager (ACM) can issue public certificates from trusted certificate authorities (CAs) such as Amazon Trust Services at no additional cost. These certificates support TLS 1.2 and 1.3 and are automatically renewed, minimizing operational overhead. ACM public certificates are trusted by major browsers because they are issued by a public CA. Option A is incorrect because CloudHSM is used for hardware-based key management, not for issuing public certificates; importing a certificate from CloudHSM would require manual renewal. Option B is incorrect because CloudFront's default certificate is for CloudFront distributions, not for ALBs; using CloudFront would introduce unnecessary complexity and cost. Option C is incorrect because self-signed certificates are not trusted by browsers and would require manual renewal and distribution.

Answer

Use AWS CloudHSM to generate a certificate and import it into ACM

Answer

Configure CloudFront in front of the ALB and use a CloudFront default certificate

Answer

Generate a self-signed certificate on the EC2 instance and upload it to ACM, then associate it with the ALB

Question 20

A company is using AWS Systems Manager Session Manager to provide secure shell access to EC2 instances without opening inbound ports. Which of the following is a requirement for this setup?

Accepted Answer

The EC2 instance must have an IAM role that allows SSM actions.. AWS Systems Manager Session Manager establishes a secure shell connection to EC2 instances without requiring inbound ports. The EC2 instance must have an IAM role attached that includes the AWS managed policy AmazonSSMManagedInstanceCore, which grants permissions for the SSM agent to communicate with the Systems Manager service. This IAM role is essential because the SSM agent uses AWS credentials from the instance metadata to authenticate and establish a bidirectional control channel via HTTPS (port 443) to the Systems Manager endpoint, not through traditional SSH.

Answer

The EC2 instance must be in a public subnet.

Answer

The EC2 instance must have a public IP address.

Answer

The security group must allow inbound SSH from 0.0.0.0/0.