DOP-C02 Configuration Management and IaC Practice Question
A company uses AWS CloudFormation to deploy a web application across multiple AWS accounts using StackSets. The DevOps team notices that stack instance updates are failing in some accounts with the error: 'Insufficient IAM permissions to perform the action'. The team has already verified that the StackSet IAM role has the necessary permissions. What is the most likely cause of this issue?
⚠ Common exam trap
Candidates often assume the error is due to missing permissions on the StackSet IAM role itself, but the DOP-C02 exam tests the understanding that StackSets require a trust chain where the target account's execution role must explicitly trust the management account's StackSet IAM role.
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 target accounts do not have the necessary trust policy to allow the StackSet IAM role to assume the execution role.
StackSets require a trust relationship between the StackSet IAM role (in the management account) and an execution role in each target account. Even if the StackSet IAM role has full permissions, the target accounts must have a trust policy that allows the StackSet IAM role to assume the execution role. Without this trust policy, the assumption fails, resulting in the 'Insufficient IAM permissions' error.
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 target accounts have reached the limit of 200 stacks per region.
Why it's wrong here
The 200-stack limit is a service quota that, when exceeded, returns errors such as StackLimitExceeded or LimitExceeded, not an access-denied or AssumeRole failure. The deployment error described points to an IAM authorization problem—the StackSet’s management role cannot assume the execution role in the target account. A limit would be unaffected by trust policies or permission settings, so the quota is not the cause.
- ✓
The target accounts do not have the necessary trust policy to allow the StackSet IAM role to assume the execution role.
Why this is correct
AWS CloudFormation StackSets require a trust relationship between the IAM role used to administer the StackSet (in the management account) and an execution role in each target account. If the execution role’s trust policy does not include the StackSet IAM role (or the appropriate account) as a trusted principal, the sts:AssumeRole call fails with an access-denied error. This trust policy is what authorizes the management account’s role to assume the target execution role, so its absence directly produces the reported failure.
- ✗
AWS Organizations has a service control policy (SCP) that denies the required action, but the StackSet IAM role has full admin permissions.
Why it's wrong here
An SCP denying the required action would still be plausible because SCPs can override IAM policies, but the failure would surface as an authorization error at the SCP layer, not as a missing trust relationship. In this scenario, the error is specifically an AssumeRole failure caused by the target execution role’s trust policy, not by an SCP evaluation. The StackSet IAM role may have full admin permissions in IAM, but SCPs operate independently of trust policies and would not prevent the role from being trusted; they would instead block the actual action after assumption, which is not what the error shows.
- ✗
The StackSet name contains invalid characters that are not allowed in some accounts.
Why it's wrong here
StackSet naming rules—alphanumeric characters and hyphens only—are enforced uniformly by CloudFormation across all AWS accounts; a name that is valid for one account is valid for any other. An invalid character would cause the StackSet to fail during creation or update in the management account, before any deployment to target accounts occurs. The reported error is an IAM trust-policy issue during cross-account role assumption, which has nothing to do with the StackSet name, so this cannot be the cause.
Go deeper
Related to this question
About these practice questions
Courseiva writes every DOP-C02 question from scratch — 251 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on DOP-C02
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company uses AWS CloudFormation StackSets to deploy a VPC across multiple AWS accounts in AWS Organizations. The StackSet is created with self-managed permissions. The deployment fails in some accounts with the error: 'Insufficient IAM permissions to create resources'. What is the most likely cause of this failure?
hard- A.The StackSet does not support deploying to more than one account
- ✓ B.The execution IAM role is not created in the target accounts
- C.The administrator account does not have a service-linked role for StackSets
- D.The target accounts have reached their resource service quotas
Why B: With self-managed permissions in AWS CloudFormation StackSets, the administrator account does not automatically create the necessary IAM roles in target accounts. The execution IAM role must be manually created in each target account to grant StackSets the permissions required to create resources. The error 'Insufficient IAM permissions to create resources' directly indicates that this execution role is missing or lacks the required policies.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DOP-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DOP-C02 exam.