DVA-C02 Security Practice Test 18 — 15 Questions

Question 1

A developer needs to grant an IAM role in Account B read-only access to objects in an S3 bucket in Account A. The bucket is encrypted with server-side encryption using AWS KMS (SSE-KMS) with a customer managed key (CMK) in Account A. Which combination of policies is required for the cross-account access to succeed?

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

Accepted Answer

The bucket policy in Account A grants s3:GetObject to the role, the KMS key policy grants kms:Decrypt to the role, and the role in Account B has an IAM policy allowing s3:GetObject and kms:Decrypt. Cross-account access to an SSE-KMS encrypted S3 bucket requires three layers of permissions: the bucket policy in Account A must grant s3:GetObject to the IAM role in Account B, the KMS key policy must grant kms:Decrypt to the same role, and the role's IAM policy in Account B must allow both s3:GetObject and kms:Decrypt. Without any one of these, the request will fail due to either an S3 authorization error or a KMS decryption failure.

Answer

The bucket policy in Account A grants s3:GetObject to the role, and the role in Account B has an IAM policy allowing s3:GetObject. No KMS permissions are needed because SSE-KMS uses AWS managed keys by default.

Answer

The bucket policy in Account A grants s3:GetObject to the role, and the KMS key policy grants kms:Decrypt to the role. The role in Account B does not need additional IAM policies because the bucket and key policies provide sufficient permissions.

Answer

Only the bucket policy in Account A needs to grant s3:GetObject to the role. KMS is not involved because the bucket is encrypted with SSE-KMS but the role can decrypt using the default KMS key.

Question 2

A developer is storing an API secret for a third-party service in AWS Secrets Manager. The secret needs to be accessed by an AWS Lambda function that runs in a VPC. The Lambda function must have the minimum required permissions. Which IAM policy statement should the developer attach to the Lambda execution role?

Accepted Answer

A policy that grants secretsmanager:GetSecretValue for the specific secret ARN and includes a condition for aws:SourceVpce to restrict access to the VPC endpoint. It grants the minimum required permission (secretsmanager:GetSecretValue) scoped to the specific secret ARN, and uses the aws:SourceVpce condition key to restrict access to the VPC endpoint used by the Lambda function. This ensures that only requests originating from the specified VPC endpoint can retrieve the secret, aligning with the principle of least privilege and the requirement that the Lambda function runs in a VPC.

Answer

A policy that grants secretsmanager:GetSecretValue for all secrets in the account

Answer

A policy that grants secretsmanager:GetSecretValue for the secret and includes a condition for aws:SourceIp

Answer

A policy that grants secretsmanager:GetSecretValue for the secret and includes a condition for ec2:Vpc

Question 3

A developer is building an application that needs to read a secret API key from AWS Secrets Manager. The application runs on an EC2 instance that is part of an Auto Scaling group. The developer wants to ensure that only this application can retrieve the secret. Which set of steps should the developer take?

Accepted Answer

Store the secret in Secrets Manager, attach an IAM role to the EC2 instance that grants permission to read the secret, and configure the application to retrieve the secret using the AWS SDK. It follows the principle of least privilege and uses IAM roles, which are the secure and recommended way to grant EC2 instances permissions to access AWS Secrets Manager. By attaching an IAM role to the EC2 instance, the application can securely retrieve the secret using the AWS SDK without embedding long-term credentials in code or configuration files. This ensures that only instances with that role can read the secret, and the credentials are automatically rotated by AWS.

Answer

Store the secret in Secrets Manager, create an IAM user with a policy to read the secret, and embed the user's credentials in the application code

Answer

Store the secret as an environment variable in the EC2 user data

Answer

Store the secret in a configuration file on the instance and restrict file permissions

Question 4

A developer is designing an application that will process credit card payments and store them temporarily in an Amazon DynamoDB table. The developer must ensure that the payment data is encrypted at rest and that the encryption key is managed by the company's security team using AWS KMS. Which type of encryption should the developer enable on the DynamoDB table?

Accepted Answer

Server-side encryption with a customer-managed KMS key. The requirement specifies that the encryption key must be managed by the company's security team. Server-side encryption (SSE) with a customer-managed KMS key allows the company to create, rotate, and control access to the KMS key used to encrypt the DynamoDB table at rest. This gives the security team full control over the encryption key lifecycle, meeting the stated requirement.

Answer

Server-side encryption with an AWS managed KMS key

Answer

Client-side encryption

Answer

Static key encryption

Question 5

A company uses AWS KMS customer master keys (CMKs) to encrypt sensitive data in Amazon S3. A compliance requirement mandates that the backing keys for the CMKs be automatically rotated every year. The developer must implement this with minimal operational overhead. Which solution meets the requirement?

Accepted Answer

Enable automatic key rotation for the CMK in AWS KMS.. AWS KMS supports automatic key rotation for customer managed CMKs. When enabled, KMS automatically rotates the backing key annually (approximately every 365 days) with no additional operational overhead. This satisfies the compliance requirement for yearly rotation without manual intervention.

Answer

Create a new CMK every year and update the S3 bucket policy to use the new key.

Answer

Use an AWS managed key (aws/s3) which automatically rotates annually.

Answer

Use SSE-S3 encryption with automatically rotated keys instead of KMS.

Question 6

A company manages multiple AWS accounts using AWS Organizations. A developer needs to allow an IAM role in the production account to read objects from an S3 bucket in the development account. The bucket is encrypted with an AWS KMS customer managed key (CMK) in the development account. Which of the following is required to enable this cross-account access?

Accepted Answer

Add a bucket policy allowing the production account's IAM role and a KMS key policy granting the same role.. Cross-account access to an S3 bucket encrypted with a KMS customer managed key requires both a bucket policy that grants the production account's IAM role s3:GetObject permission and a KMS key policy that grants the same role kms:Decrypt permission. The bucket policy authorizes the S3 operation, while the key policy authorizes decryption of the object; both policies must explicitly allow the cross-account principal.

Answer

Grant the production account's root user access to the KMS key and the S3 bucket.

Answer

Create an IAM role in the production account with permissions to access the S3 bucket and KMS key.

Answer

Enable S3 bucket logging to allow cross-account access.

Question 7

A company stores sensitive documents in an Amazon S3 bucket. The security team requires that all objects uploaded must be encrypted at rest using a specific customer-managed AWS KMS key (key-id: 1234-5678). The developer must enforce this by denying any PutObject request that does not use the correct key. Which S3 bucket policy condition should be used?

Accepted Answer

s3:x-amz-server-side-encryption-aws-kms-key-id with value 'arn:aws:kms:us-east-1:123456789012:key/1234-5678'. The condition key `s3:x-amz-server-side-encryption-aws-kms-key-id` allows you to enforce that a specific customer-managed AWS KMS key (identified by its full ARN) is used for server-side encryption. By denying PutObject requests that do not match this key ID, the security team ensures all uploaded objects are encrypted at rest with the required KMS key.

Answer

s3:x-amz-server-side-encryption with value 'aws:kms'

Answer

s3:x-amz-acl with value 'bucket-owner-full-control'

Answer

aws:SourceArn with value the bucket ARN

Question 8

A company uses AWS Organizations with multiple accounts. A developer needs to grant an IAM user in Account A (111111111111) read-only access to an S3 bucket in Account B (222222222222). The bucket is encrypted with SSE-S3. Which combination of policies is required for cross-account access?

Accepted Answer

Bucket policy in Account B granting s3:GetObject to the IAM user ARN, and an IAM policy in Account A allowing s3:GetObject.. Cross-account S3 access requires both a bucket policy in the resource account (Account B) that explicitly grants the IAM user ARN from Account A the s3:GetObject permission, and an IAM policy in the user's account (Account A) that allows the same action. The bucket policy acts as a resource-based policy that authorizes the cross-account principal, while the IAM policy is necessary to authorize the user to make the request. SSE-S3 encryption does not require additional configuration because S3 handles decryption automatically for authorized users.

Answer

Bucket policy in Account B granting s3:GetObject to Account A's root user ARN, and an IAM policy in Account A allowing s3:GetObject.

Answer

Bucket policy in Account B granting s3:GetObject to the IAM user ARN, and no IAM policy in Account A is needed.

Answer

IAM policy in Account A allowing s3:GetObject, and an S3 Access Point in Account B configured for cross-account access.

Question 9

A company has an S3 bucket that stores sensitive data. They want to ensure that any object uploaded to the bucket is automatically encrypted with server-side encryption using AWS KMS (SSE-KMS). They also want to deny any uploads that do not specify the correct encryption. Which bucket policy condition should be used to enforce this requirement?

Accepted Answer

s3:x-amz-server-side-encryption equals aws:kms. The condition `s3:x-amz-server-side-encryption equals aws:kms` enforces that any PUT request to the S3 bucket must include the `x-amz-server-side-encryption` header set to `aws:kms`, which triggers SSE-KMS encryption. This policy condition ensures that objects uploaded without specifying SSE-KMS are denied, meeting the requirement to automatically encrypt all uploaded objects with AWS KMS.

Answer

s3:x-amz-server-side-encryption equals AES256

Answer

s3:x-amz-server-side-encryption-aws-kms-key-id equals a specific key ARN

Answer

aws:SecureTransport equals true

Question 10

A developer is deploying a containerized application on Amazon ECS with the Fargate launch type. The application needs to read data from an Amazon S3 bucket. The developer wants to follow the principle of least privilege. How should the developer grant the necessary permissions to the ECS tasks?

Accepted Answer

Create an IAM task role and reference it in the task definition using the 'taskRoleArn' parameter.. Amazon ECS with the Fargate launch type supports IAM task roles, which allow you to assign an IAM role to the ECS task itself. By referencing the IAM task role in the task definition using the 'taskRoleArn' parameter, the containerized application can securely obtain temporary credentials from the ECS container agent via the AWS STS service, adhering to the principle of least privilege without embedding long-lived credentials.

Answer

Store AWS access keys as environment variables in the task definition.

Answer

Create an IAM user and embed its credentials in the container image.

Answer

Use an S3 bucket policy that grants access based on the security group of the ECS tasks.

Question 11

A company has an IAM policy that allows access to an S3 bucket only if the request comes from a specific VPC endpoint. The developer notices that requests from an EC2 instance in that VPC are being denied. What is the most likely cause?

Accepted Answer

The VPC endpoint policy does not allow the required S3 action for the principal. The VPC endpoint policy is an additional layer of access control that can explicitly deny actions even if the bucket policy allows them. If the endpoint policy does not grant the required S3 action (e.g., s3:GetObject) for the IAM principal (the EC2 instance's role), requests will be denied regardless of the bucket policy. This is a common misconfiguration where developers focus only on the bucket policy and overlook the endpoint policy.

Answer

The bucket policy does not have a condition checking aws:SourceVpce

Answer

The route table does not have a route to the S3 endpoint

Answer

The security group does not allow outbound HTTPS traffic

Question 12

A company uses AWS KMS to encrypt data at rest in S3. The security team requires that all objects uploaded to a specific S3 bucket must be encrypted with a specific KMS key (key ID: xyz). The developer needs to enforce this by denying any PutObject request that does not use the correct key. Which bucket policy condition should be used?

Accepted Answer

s3:x-amz-server-side-encryption-aws-kms-key-id. The `s3:x-amz-server-side-encryption-aws-kms-key-id` condition key allows you to enforce that a specific KMS key ID (e.g., `xyz`) is used for server-side encryption with AWS KMS (SSE-KMS). By including this condition in a bucket policy with a `Deny` effect, any `PutObject` request that does not specify the required key ID will be denied, meeting the security team's requirement.

Answer

kms:EncryptionContext

Answer

s3:EncryptionAlgorithm

Answer

kms:GrantOperations

Question 13

A company stores sensitive data in Amazon S3. A developer needs to implement a solution that automatically encrypts objects at rest using a key that is rotated annually. The developer must minimize operational overhead. Which solution meets these requirements?

Accepted Answer

Use Server-Side Encryption with AWS KMS-Managed Keys (SSE-KMS) with automatic key rotation.. SSE-KMS with automatic key rotation meets the requirement for annual key rotation with minimal operational overhead because AWS KMS can automatically rotate the customer master key (CMK) every year (365 days) without any manual intervention. This ensures that objects in S3 are encrypted at rest using a key that is rotated on schedule, while the developer does not need to manage the rotation process.

Answer

Use Server-Side Encryption with S3-Managed Keys (SSE-S3) and set key rotation policy.

Answer

Use Server-Side Encryption with Customer-Provided Keys (SSE-C) and manually rotate keys.

Answer

Use Client-Side Encryption with KMS.

Question 14

A developer launches an Amazon EC2 instance that needs to read and write data to an Amazon DynamoDB table. The developer must follow the principle of least privilege and ensure that no long-term credentials are stored on the instance. Which approach should the developer use?

Accepted Answer

Create an IAM role with the necessary DynamoDB permissions, and attach the role to the EC2 instance profile. The SDK will automatically retrieve temporary credentials from the instance metadata.. It uses an IAM role attached to the EC2 instance profile, which allows the AWS SDK to automatically retrieve temporary credentials from the instance metadata service (IMDS). This follows the principle of least privilege by granting only the necessary DynamoDB permissions and eliminates the need to store any long-term credentials on the instance, as the credentials are rotated automatically by AWS STS.

Answer

Create an IAM user with programmatic access, store the access key and secret key in a configuration file on the EC2 instance.

Answer

Store the DynamoDB credentials in AWS Systems Manager Parameter Store as a SecureString, and retrieve them from the EC2 instance at runtime.

Answer

Use a Lambda function to generate temporary credentials for the EC2 instance and pass them via user data at launch.

Question 15

A company requires that all data in Amazon S3 be encrypted at rest using server-side encryption with a customer-managed KMS key. The developer needs to ensure that any object uploaded without the x-amz-server-side-encryption header set to aws:kms is denied. How can this be enforced?

Accepted Answer

Use a bucket policy that denies s3:PutObject if the encryption condition is not met.. An S3 bucket policy with a condition that denies s3:PutObject unless the `s3:x-amz-server-side-encryption` header equals `aws:kms` enforces server-side encryption with a customer-managed KMS key at the API level. This policy explicitly rejects any upload that does not include the required encryption header, ensuring compliance even if default encryption is bypassed or misconfigured.

Answer

Configure default encryption on the bucket with SSE-KMS.

Answer

Enable S3 Object Lock.

Answer

Use a CloudTrail trail to monitor uploads.