Amazon Web Services AWS Certified Professional SAP-C02 Question # 125 Topic 13 Discussion

 The company should create a resource-based IAM policy that includes conditions for specific DynamoDB attributes (fine-grained access control). The company should attach the policy to the DynamoDB table. In the marketing team’s account, the company should create an IAM role that has permissions to access the DynamoDB table in the finance team’s account. This solution will meet the requirements because a resource-based IAM policy is a policy that you attach to an AWS resource (such as a DynamoDB table) to control who can access that resource and what actions they can perform on it. You can use IAM policy conditions to specify fine-grained access control for DynamoDB items and attributes. For example, you can allow or deny access to specific attributes of all items in a table by matching on attribute names1. By creating a resource-based policy that allows access to only specific attributes of the DynamoDB table and attaching it to the table, the company can restrict access to confidential data. By creating an IAM role in the marketing team’s account that has permissions to access the DynamoDB table in the finance team’s account, the company can enable cross-account access.

The other options are not correct because:

Creating an SCP to grant the marketing team’s AWS account access to the specific attributes of the DynamoDB table would not work because SCPs are policies that you can use with AWS Organizations to manage permissions in your organization’s accounts. SCPs do not grant permissions; instead, they specify the maximum permissions that identities in an account can have2. SCPs cannot be used to specify fine-grained access control for DynamoDB items and attributes.

Creating an IAM role in the finance team’s account by using IAM policy conditions for specific DynamoDB attributes and establishing trust with the marketing team’s account would not work because IAM roles are identities that you can create in your account that have specific permissions. You can use an IAM role to delegate access to users, applications, or services that don’t normally have access to your AWS resources3. However, creating an IAM role in the finance team’s account would not restrict access to specific attributes of the DynamoDB table; it would only allow cross-account access. The company would still need a resource-based policy attached to the table to enforce fine-grained access control.

Creating an IAM role in the finance team’s account to access the DynamoDB table and using an IAM permissions boundary to limit the access to the specific attributes would not work because IAM permissions boundaries are policies that you use to delegate permissions management to other users. You can use permissions boundaries to limit the maximum permissions that an identity-based policy can grant to an IAM entity (user or role)4. Permissions boundaries cannot be used to specify fine-grained access control for DynamoDB items and attributes.

References:

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/specifying-conditions.html

https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_scps.html

https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html

https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_boundaries.html