mediumMultiple ChoiceObjective-mapped

CISA Practice Question: Refer to the exhibit

Exhibit

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "s3:*",
      "Resource": "*",
      "Condition": {
        "StringEquals": {
          "aws:SourceAccount": "123456789012"
        }
      }
    }
  ]
}

Refer to the exhibit. The IAM policy is intended to allow only requests originating from account 123456789012 to perform any S3 actions. Why does the policy NOT achieve this objective?

⚠ Common exam trap

A common mix-up: candidates assume 'aws:SourceAccount' works identically in both identity-based and resource-based policies, but it only restricts cross-account access and has no effect on same-account requests, leading to a false sense of security.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

The condition key 'aws:SourceAccount' only applies when the request is made from another account; it does not restrict access to resources owned by the same account.

The 'aws:SourceAccount' condition key is designed for use in resource-based policies (like S3 bucket policies) to prevent cross-account confusion of resources. It does not restrict access within the same account; it only validates the source account when the request originates from a different account. Since the policy is an IAM identity-based policy (attached to a user/role), the 'aws:SourceAccount' condition is not evaluated for same-account requests, so any principal in account 123456789012 can still perform S3 actions without being restricted by this condition.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
The Resource element is set to "*", which allows all actions on all resources regardless of the condition.
Why it's wrong here
The condition is evaluated, but it does not filter resources by ownership; the policy still allows access to any bucket from the source account.
✓
The condition key 'aws:SourceAccount' only applies when the request is made from another account; it does not restrict access to resources owned by the same account.
Why this is correct
The condition key is misapplied; it does not limit the S3 resources to those in the specified account.
✗
The policy should include a Deny statement for all other accounts to be effective.
Why it's wrong here
A Deny statement could help but would not fix the condition key issue; the policy intrinsically allows all S3 actions from the specified source account.
✗
The Version element is incorrect and should be updated to the latest version.
Why it's wrong here
The version is correct; policy syntax is not the issue.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

Go deeper

CISA Practice Question: Refer to the exhibit

Exhibit

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

Related to this question