DBS-C01 Database Security — Timed 15 Questions

Question 1

A company runs an Amazon RDS for MySQL DB instance in a VPC. Security requirements mandate that only specific EC2 instances in the same VPC can connect to the database. The security group attached to the RDS instance currently allows inbound traffic on port 3306 from 0.0.0.0/0. Which combination of steps should a database specialist take to meet the security requirement without impacting existing application connectivity? (Choose two.)

Accepted Answer

Remove the inbound rule for 0.0.0.0/0 on the RDS security group.. Option B is correct because removing the overly permissive inbound rule for 0.0.0.0/0 on the RDS security group eliminates unrestricted access, which is a direct violation of the security requirement. Option C is correct because adding an inbound rule that references the security group ID of the EC2 instances allows traffic only from those instances, leveraging security group referencing for granular, stateful access control within the same VPC.

Answer

Modify the network ACL for the DB subnet to allow inbound port 3306 from the EC2 instance's private IP.

Answer

Modify the DB subnet group to place the RDS instance in a public subnet with a route to the EC2 instance.

Answer

Add an inbound rule to the RDS security group allowing traffic from the VPC CIDR on port 3306.

Question 2

A company uses Amazon DynamoDB with a table that stores sensitive customer data. The security team requires that all data at rest be encrypted using a customer-managed AWS KMS key (CMK). Additionally, the company needs to ensure that only specific IAM roles can access the table. Which solution meets these requirements with the least operational overhead?

Accepted Answer

Configure the DynamoDB table to use AWS KMS encryption with a CMK. Create an IAM role with a policy that grants access to the table and includes a condition that the encryption context matches the CMK.. Option D is correct because it combines DynamoDB encryption at rest with a customer-managed KMS CMK and uses an IAM role policy with an encryption context condition. This ensures that only specific IAM roles can access the table, and the encryption context condition ties the KMS key usage to the table, providing fine-grained access control with minimal operational overhead. The encryption context is automatically set by DynamoDB to the table ARN, so the condition key `kms:EncryptionContext:aws:dynamodb:tableName` can be used to restrict decryption to that specific table.

Answer

Enable encryption at rest using AWS KMS with a CMK and use column-level encryption with AWS KMS to restrict access.

Answer

Attach a resource-based policy to the DynamoDB table that grants access only to the specific IAM roles.

Answer

Use a DynamoDB Accelerator (DAX) cluster with encryption at rest using a CMK, and attach a resource-based policy to the table.

Answer

Configure the DynamoDB table to use AWS KMS encryption with a CMK, and attach a key policy to the CMK that allows only the specific IAM roles.

Question 3

A database specialist is troubleshooting a connectivity issue with an Amazon RDS for PostgreSQL instance. The instance is in a VPC with a public subnet. The security group allows inbound traffic on port 5432 from the application server's IP address. The application server is in the same VPC but in a private subnet. Despite the security group configuration, the application cannot connect. Which action should the specialist take to resolve the issue?

Accepted Answer

Update the security group inbound rule to allow traffic from the application server's private IP address.. Option E is correct because the application server is in a private subnet, so it communicates with the RDS instance using its private IP address. The security group inbound rule must allow traffic from the application server's private IP (or the security group of the application server) on port 5432. The current rule only allows the application server's public IP, which is not used for traffic within the VPC, causing the connection failure.

Answer

Launch the RDS instance in the default VPC.

Answer

Change the DB subnet group to include the application server's subnet.

Answer

Add a network ACL rule allowing inbound traffic on port 5432 from the application server's public IP.

Answer

Modify the RDS instance to be publicly accessible.

Question 4

A company stores financial data in an Amazon Aurora MySQL DB cluster. The security team requires that database audit logs be stored in Amazon CloudWatch Logs and encrypted at rest using a customer-managed KMS key. The database specialist enables audit log publishing to CloudWatch Logs and specifies a KMS key for log encryption. However, the audit logs are not appearing in CloudWatch Logs. What is the most likely cause?

Accepted Answer

The IAM role used for publishing logs does not have the necessary permissions to use the KMS key for CloudWatch Logs.. When publishing database audit logs to CloudWatch Logs with a customer-managed KMS key, the IAM role used by RDS must have explicit permissions for the `kms:Encrypt` and `kms:Decrypt` actions on the KMS key. Without these permissions, RDS cannot encrypt the log stream, and the logs will not appear. Option C correctly identifies this missing permission as the most likely cause.

Answer

The CloudWatch Logs log group does not exist and RDS cannot create it automatically.

Answer

The DB cluster is not configured to export error logs, only audit logs.

Answer

CloudWatch Logs does not support encryption with customer-managed KMS keys for audit logs.

Answer

The audit log parameter is static and requires a DB cluster reboot after modification.

Question 5

A company uses Amazon ElastiCache for Redis to cache session data. The security team requires that all data in transit be encrypted. The Redis cluster currently does not have encryption in transit enabled. The database specialist needs to enable encryption in transit with minimal downtime. Which action should the specialist take?

Accepted Answer

Create a new Redis cluster with encryption in transit enabled, and migrate the data from the existing cluster.. Encryption in transit for ElastiCache for Redis can only be enabled at cluster creation time; it cannot be added to an existing cluster. Therefore, the correct approach is to create a new Redis cluster with encryption in transit enabled, migrate the session data from the existing cluster (e.g., using replication or a manual export/import), and then redirect application traffic to the new cluster. This ensures minimal downtime if the migration is performed during a maintenance window or using a blue/green deployment strategy.

Answer

Update the Redis parameter group to enable the 'encryption-in-transit' parameter and reboot the cluster.

Answer

Use a security group to enforce encrypted connections by allowing only TLS traffic.

Answer

Modify the existing Redis cluster to enable encryption in transit using the AWS CLI.

Answer

Enable encryption in transit on the existing cluster by using the AWS Management Console.

Question 6

A company uses Amazon RDS for SQL Server with Multi-AZ deployment. The security team wants to ensure that all database connections use SSL/TLS encryption. Which TWO actions should the database specialist take to enforce SSL connections? (Choose two.)

Accepted Answer

Create a server-level trigger that requires SSL for all logins.. Option C is correct because SQL Server allows you to create a server-level DDL trigger that checks the login event and enforces SSL by examining the `@@OPTIONS` or `encrypt_option` in `sys.dm_exec_connections`. This is a supported method to force SSL for all connections to an RDS for SQL Server instance. Option E is correct because setting the `rds.force_ssl` parameter to 1 in the DB parameter group is the native RDS mechanism to enforce SSL/TLS for all connections to the DB instance.

Answer

Use the RDS Console to enable 'Force SSL' on the DB instance.

Answer

Modify the DB parameter group to set 'require_secure_transport' to ON.

Answer

Add an inbound rule to the security group that only allows traffic on port 1433 from IP addresses that use SSL.

Question 7

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The security team requires that all data be encrypted at rest using a customer-managed KMS key. Additionally, the database should be accessible only from a specific VPC. Which THREE steps should the database specialist take to meet these requirements? (Choose three.)

Accepted Answer

Configure the security group for the RDS instance to allow inbound traffic only from the application security group.. Option A is correct because security groups act as a virtual firewall for RDS instances. By configuring the security group to allow inbound traffic only from the application security group, you restrict database access to specific application servers, meeting the requirement that the database be accessible only from a specific VPC.

Answer

Create a VPC endpoint for RDS and associate it with the DB instance.

Answer

Store the encryption key in Amazon S3 and configure RDS to use it.

Question 8

A company uses Amazon RDS for MySQL with encryption at rest enabled. The security team mandates that all access to the database must be authenticated using IAM database authentication. The database administrator has created a user 'app_user' and granted appropriate privileges. However, when the application tries to connect using an IAM authentication token, it receives an 'Access denied' error. Which action should be taken to resolve this issue?

Accepted Answer

Ensure the IAM role used by the application has a name that matches the database user 'app_user' and has the necessary policy attached.. Option C is correct because IAM database authentication for RDS MySQL requires that the database user name matches the IAM role or user name used to generate the authentication token. The IAM role must have a policy that allows the `rds-db:connect` action with a resource ARN specifying the database user. Without this exact match, the authentication token is rejected, resulting in an 'Access denied' error.

Answer

Create a password for 'app_user' and use that password in the connection string.

Answer

Modify the security group to allow inbound traffic on port 3306 from the application's IP address.

Answer

Download the latest Amazon RDS CA certificate and add it to the application trust store.

Question 9

A company is designing a multi-tier application that uses Amazon RDS for PostgreSQL. The application must encrypt data at rest and in transit. Which combination of steps should be taken to meet these requirements? (Choose the single best answer.)

Accepted Answer

Enable encryption at rest when launching the RDS instance, and configure the DB parameter group to require SSL connections.. Option B is correct because Amazon RDS for PostgreSQL supports encryption at rest only when enabled at instance launch, and SSL/TLS encryption in transit is enforced by configuring the DB parameter group to require SSL connections (e.g., setting `rds.force_ssl=1`). Encryption at rest cannot be added after creation, and SSL ensures data is encrypted between the application and the database.

Answer

Use client-side encryption for data before sending to RDS, and enable encryption at rest after the instance is created.

Answer

Launch the RDS instance without encryption, then enable encryption at rest using the AWS Console.

Answer

Use AWS KMS to encrypt the connection between the application and RDS.

Question 10

A financial services company uses Amazon DynamoDB to store sensitive customer data. The security team requires that all data at rest be encrypted using a customer-managed AWS KMS key (CMK) with automatic rotation enabled. The DynamoDB table was created with the default AWS-managed key. Which steps are necessary to transition to a customer-managed CMK while minimizing downtime and data loss?

Accepted Answer

Export the table data to Amazon S3, create a new DynamoDB table with the new CMK, import the data, and update the application to use the new table.. Option B is correct because DynamoDB does not support in-place modification of the encryption key for an existing table. To transition from an AWS-managed key to a customer-managed CMK, you must export the table data to Amazon S3, create a new DynamoDB table configured with the new CMK, import the data, and update the application to point to the new table. This approach minimizes downtime by allowing the original table to serve reads/writes during the export and import process, and avoids data loss by using DynamoDB's native export and import features.

Answer

Modify the DynamoDB table to update the encryption key to the new CMK using the AWS Console.

Answer

Disable encryption at rest, then re-enable it with the new CMK.

Answer

Update the KMS key policy to grant DynamoDB access to the new CMK, then rotate the key.

Question 11

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The compliance team requires that all database connections use SSL/TLS and that users authenticate using IAM database authentication. The database migration is completed, but the application team reports that connections using IAM authentication are failing. The company has already enabled IAM database authentication on the RDS instance. What is the most likely cause of the failure?

Accepted Answer

The database user has not been granted the necessary privileges for IAM authentication.. Option C is correct because IAM database authentication requires that the database user be created with the `IDENTIFIED WITH AWS_AUTHENTICATION` clause in Oracle. Without this privilege, the RDS instance will reject IAM-authenticated connections even if IAM authentication is enabled at the instance level. The application team must ensure the database user has been granted the `AWS_ORACLE_EXTENSIONS` role and that the user is mapped to an IAM policy allowing `rds-db:connect`.

Answer

The application is using an outdated root CA certificate for SSL.

Answer

The Security Group does not allow inbound traffic from the application.

Answer

The RDS instance is using a different KMS key for encryption.

Question 12

A company is using Amazon RDS for MySQL with Multi-AZ deployment. The security team wants to ensure that database administrators cannot view sensitive data. Which TWO actions should be taken to achieve this goal?

Accepted Answer

Use IAM database authentication for application access.. Option A is correct because IAM database authentication allows you to authenticate to your RDS MySQL instance using an IAM user or role instead of a traditional database password. This eliminates the need for database administrators to know or manage database credentials, as they can only access the database through IAM policies that grant specific, auditable permissions. By using IAM authentication, you enforce a separation of duties where DBAs cannot view sensitive data unless explicitly authorized by IAM policies.

Answer

Enable audit logging to capture all data access.

Answer

Enable encryption at rest using a customer-managed KMS key.

Answer

Disable query logging to prevent sensitive data from being written to logs.

Question 13

A company is designing a disaster recovery strategy for an Amazon Aurora MySQL database. The database stores sensitive data that must be encrypted at rest. The primary region is us-east-1, and the secondary region is us-west-2. Which THREE steps are required to set up cross-region replication with encryption at rest?

Accepted Answer

Use a multi-Region KMS key to encrypt the Aurora cluster in the primary region.. Option A is correct because using a multi-Region KMS key allows the Aurora cluster in the primary region to be encrypted at rest with a key that can be replicated to the secondary region, ensuring that the cross-region read replica can decrypt the data without needing to re-encrypt it. This key is replicated automatically by AWS KMS to the secondary region, maintaining the same key material for encryption and decryption across regions.

Answer

Ensure the DB cluster parameter group is the same in both regions.

Answer

Create a cross-Region read replica in the secondary region.

Question 14

A security engineer is troubleshooting an issue where an application using IAM role 'app-role' with a trust policy to assume the 'app-user' user is unable to decrypt an RDS database that uses a customer-managed KMS key. The above key policy is attached to the KMS key. What is the likely cause of the failure?

Accepted Answer

The principal in the policy is 'app-user', but the application uses an IAM role that does not have the necessary permissions.. Option C is correct because the KMS key policy specifies the principal as 'app-user', which is an IAM user. However, the application uses an IAM role 'app-role' to make the decryption requests. Since the principal in the key policy does not include the role or its associated permissions, the KMS key policy denies access to the role, causing the decryption failure. The trust policy on the role allows the user to assume it, but that does not grant the role any KMS permissions unless explicitly added.

Answer

The 'kms:ViaService' condition requires the request to come from RDS, but the application is making KMS API calls directly.

Answer

The policy has a missing 'Effect': 'Deny' statement that is blocking access.

Answer

The condition 'kms:ViaService' restricts the key to be used only with RDS, but the application is using a different service.

Question 15

A company has a production Amazon RDS for SQL Server database that stores financial data. The database administrator wants to audit all access to sensitive columns (e.g., credit card numbers) using the SQL Server Audit feature. The database is part of a Multi-AZ deployment. The administrator has enabled audit logging to the 'DEFAULT' file audit target, but the audit files are being written to the local instance storage and are not being retained after failover. The compliance team requires that audit logs be stored in Amazon S3 for at least 7 years. The administrator has set up an event subscription to send database events to an S3 bucket using AWS DMS, but the audit logs are not being captured. What should the administrator do to meet the compliance requirements?

Accepted Answer

Create a new SQL Server Audit target using the Amazon S3 option and configure the audit to write to an S3 bucket.. Option C is correct because Amazon RDS for SQL Server supports writing SQL Server Audit logs directly to an Amazon S3 bucket as an audit target. This is the only native method that persists audit logs beyond the instance lifecycle, ensuring they survive Multi-AZ failover and meet the 7-year retention requirement. The DEFAULT file target writes to ephemeral instance storage, which is lost on failover, and RDS event subscriptions or DMS cannot capture SQL Server Audit output.

Answer

Use RDS event subscriptions to send database audit logs to an S3 bucket.

Answer

Configure AWS DMS to continuously replicate the audit database to an S3 bucket.

Answer

Enable RDS Enhanced Monitoring and configure it to send logs to CloudWatch Logs.