- A
The bucket is encrypted with SSE-KMS and the user does not have kms:Decrypt permission
SSE-KMS requires explicit kms:Decrypt permission on the customer master key. Without it, even valid S3 permissions result in Access Denied.
- B
The bucket policy does not specify the user's ARN
Why wrong: The policy grants access to the other account's root user, which covers all IAM users in that account. Specifying specific user ARN is not required.
- C
The object's ACL is set to private
Why wrong: When a bucket policy allows access, it overrides object ACLs. A private ACL does not override an explicit allow in the bucket policy.
- D
The IAM policy does not include s3:ListBucket
Why wrong: ListBucket is required only for listing objects, not for getting an individual object. GetObject permission alone is sufficient for downloading.
Quick Answer
The answer is that the user lacks the required kms:Decrypt permission on the AWS KMS key used for server-side encryption. When an S3 bucket is configured with SSE-KMS, a successful GetObject request involves two distinct authorization checks: the S3 bucket policy and IAM policy must allow s3:GetObject, and the caller must also have explicit kms:Decrypt permission on the customer master key (CMK) to decrypt the object before it is returned. Even if the bucket policy grants access to the root user of the other account and the IAM user has an s3:GetObject policy, the missing KMS permission triggers an Access Denied error. On the DVA-C02 exam, this scenario tests your understanding that KMS permissions are a separate, often overlooked layer of access control in cross-account S3 setups. A common trap is assuming bucket policies alone govern access, but encrypted objects add a KMS authorization gate. Memory tip: think "S3 + KMS = two keys to unlock" — the S3 policy and the KMS decrypt permission.
DVA-C02 Troubleshooting and Optimization Practice Question
This DVA-C02 practice question tests your understanding of troubleshooting and optimization. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A developer is debugging an issue where an Amazon S3 bucket policy is not allowing cross-account access for a user from another AWS account. The bucket policy grants access to the other account's root user. The IAM user in the other account has an IAM policy that allows s3:GetObject on the bucket. When the user tries to download an object, they get an Access Denied error. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 bucket is encrypted with SSE-KMS and the user does not have kms:Decrypt permission
The most likely cause is that the bucket is encrypted with SSE-KMS. When an S3 bucket uses AWS KMS customer master keys (CMKs) for server-side encryption, the bucket policy granting access to the root user of the other account is not sufficient. The IAM user in the other account must also have explicit kms:Decrypt permission on the KMS key, because S3 GetObject calls require decrypting the object before returning it. Without this KMS permission, the request fails with Access Denied even though the S3 bucket policy and IAM policy appear correct.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 bucket is encrypted with SSE-KMS and the user does not have kms:Decrypt permission
Why this is correct
SSE-KMS requires explicit kms:Decrypt permission on the customer master key. Without it, even valid S3 permissions result in Access Denied.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The bucket policy does not specify the user's ARN
Why it's wrong here
The policy grants access to the other account's root user, which covers all IAM users in that account. Specifying specific user ARN is not required.
- ✗
The object's ACL is set to private
Why it's wrong here
When a bucket policy allows access, it overrides object ACLs. A private ACL does not override an explicit allow in the bucket policy.
- ✗
The IAM policy does not include s3:ListBucket
Why it's wrong here
ListBucket is required only for listing objects, not for getting an individual object. GetObject permission alone is sufficient for downloading.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume a valid S3 bucket policy and IAM policy are sufficient, forgetting that KMS encryption adds an independent authorization layer that requires explicit kms:Decrypt permissions, which is a common oversight in cross-account S3 access scenarios.
Detailed technical explanation
How to think about this question
When SSE-KMS is enabled, S3 calls KMS to decrypt the object's data key during GetObject. The IAM user must have kms:Decrypt permission on the specific KMS key, and the KMS key policy must also grant access to the user's account. This is a common pitfall because the error message from S3 is generic 'Access Denied' rather than a KMS-specific error, leading developers to overlook the KMS permission requirement. In cross-account scenarios, the KMS key policy must explicitly allow the external account's root or IAM user, and the IAM user must have the corresponding KMS action.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Troubleshooting and Optimization — study guide chapter
Learn the concepts, then practise the questions
- →
Troubleshooting and Optimization practice questions
Targeted practice on this topic area only
- →
All DVA-C02 questions
1,616 questions across all exam domains
- →
AWS Certified Developer Associate DVA-C02 study guide
Full concept coverage aligned to exam objectives
- →
DVA-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related DVA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Development with AWS Services practice questions
Practise DVA-C02 questions linked to Development with AWS Services.
Security practice questions
Practise DVA-C02 questions linked to Security.
Deployment practice questions
Practise DVA-C02 questions linked to Deployment.
Troubleshooting and Optimization practice questions
Practise DVA-C02 questions linked to Troubleshooting and Optimization.
DVA-C02 fundamentals practice questions
Practise DVA-C02 questions linked to DVA-C02 fundamentals.
DVA-C02 scenario practice questions
Practise DVA-C02 questions linked to DVA-C02 scenario.
DVA-C02 troubleshooting practice questions
Practise DVA-C02 questions linked to DVA-C02 troubleshooting.
Practice this exam
Start a free DVA-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Troubleshooting and Optimization — This question tests Troubleshooting and Optimization — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The bucket is encrypted with SSE-KMS and the user does not have kms:Decrypt permission — The most likely cause is that the bucket is encrypted with SSE-KMS. When an S3 bucket uses AWS KMS customer master keys (CMKs) for server-side encryption, the bucket policy granting access to the root user of the other account is not sufficient. The IAM user in the other account must also have explicit kms:Decrypt permission on the KMS key, because S3 GetObject calls require decrypting the object before returning it. Without this KMS permission, the request fails with Access Denied even though the S3 bucket policy and IAM policy appear correct.
What should I do if I get this DVA-C02 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
More DVA-C02 practice questions
- A developer is troubleshooting an AWS Lambda function that is triggered by an S3 event. The function occasionally fails…
- A developer needs to call AWS APIs from application code running on EC2. Which credential source should the AWS SDK use…
- A developer needs to allow an IAM user in a different AWS account to assume a role in the developer's account. The role…
- 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…
- An API Gateway HTTP API should allow access only to users authenticated by an external OIDC provider. Which authorizer t…
- A developer monitors an AWS Lambda function that processes messages from an Amazon SQS queue. CloudWatch logs show that…
Last reviewed: Jun 11, 2026
This DVA-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 DVA-C02 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.