Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A developer needs to grant temporary access to an Amazon S3 bucket for a user from a different AWS account. The developer wants to use the most secure method that does not require sharing long-term credentials. Which approach should the developer take?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
Create an IAM user in the developer's account and share the access keys
This would require sharing long-term access keys, which is a security risk. It does not use temporary credentials and violates the principle of least privilege.
B
Distractor review
Use S3 bucket policy with a condition for the external account's IAM user
While a bucket policy can grant access to an external IAM user, that user still uses long-term credentials. This is not as secure as using temporary credentials via role assumption.
C
Best answer
Use cross-account IAM roles with STS AssumeRole
This allows the external user to assume a role in the developer's account, obtaining temporary credentials. It does not require sharing long-term keys and provides fine-grained control.
D
Distractor review
Use S3 access control lists (ACLs) with the external user's canonical user ID
ACLs are a legacy permission mechanism and require the external user's canonical ID, which involves sharing long-term identifiers. They are less secure and not recommended for cross-account access.
Common exam trap
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Technical deep dive
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
- Standard ACLs match source addresses.
- Extended ACLs can match source, destination, protocol and ports.
- The first matching ACL entry is used.
- There is usually an implicit deny at the end.
TExam Day Tips
- Check inbound versus outbound direction.
- Read the ACL from top to bottom.
- Look for a broader permit or deny above the intended line.
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.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A developer is building a REST API using Amazon API Gateway that will serve static content from an Amazon S3 bucket. The API should cache responses for frequently accessed objects to reduce latency. Which API Gateway feature should the developer enable?
Question 2
A developer is running a web application on multiple Amazon EC2 instances behind an Application Load Balancer (ALB). The application needs to store user session state that must be available across all instances. The session data is small and temporary but must survive individual instance failures. Which AWS service should the developer use to store this session state?
Question 3
A developer has an AWS Lambda function that processes messages from an Amazon SQS standard queue. The function is idempotent and currently has a batch size of 10. The developer wants to increase throughput and increases the batch size to 100. After the change, CloudWatch metrics show a significant increase in throttles and the queue backlog is growing. The function's reserved concurrency is set to 10. What is the most effective action to resolve the throttling and improve throughput?
Question 4
A developer is managing an application running on Amazon EC2 instances behind an Application Load Balancer. Users report that the application becomes unresponsive after several hours, and restarting the instance temporarily fixes the issue. The developer suspects a memory leak but cannot add custom instrumentation. Which AWS service can collect memory utilization metrics and help identify the memory leak with minimal configuration?
Question 5
A developer is building a serverless web application using AWS Lambda and Amazon DynamoDB. The application needs to perform complex aggregations on data stored in DynamoDB. Which AWS service should the developer use to perform these aggregations efficiently without reading all the data into Lambda?
Question 6
A developer has an Amazon S3 bucket containing private user documents. The application must generate a time-limited URL for users to download their own documents without requiring the users to have AWS credentials. Which solution should the developer use?
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Standard ACLs match source addresses.
What is the correct answer to this question?
The correct answer is: Use cross-account IAM roles with STS AssumeRole — The most secure method for granting temporary cross-account access is to use IAM roles with AWS Security Token Service (STS) AssumeRole. The user in the other account assumes a role in the bucket owner's account, obtaining temporary credentials. Using a bucket policy directly grants access to the external IAM user, but that user has long-term credentials. Sharing access keys or using ACLs are not recommended. Therefore, cross-account IAM roles is the best approach.
What should I do if I get this DVA-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
Discussion
Loading comments…
Sign in to join the discussion.