Question 468 of 1,546
Security and CompliancemediumMultiple ChoiceObjective-mapped

SOA-C02 Practice Question: S3 bucket policy for cross-account read access…

This SOA-C02 practice question tests your understanding of security and compliance. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. A key principle to apply: s3 bucket policy. 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.

Account A owns an S3 bucket containing shared artifacts. Account B needs to read objects from the bucket. The Account A team wants to grant access without creating IAM users, sharing access keys, or creating a role in Account A that Account B assumes. How should the bucket be configured to allow Account B's IAM roles to read objects?

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

Add an S3 bucket policy on Account A's bucket with Principal set to Account B's account ID and s3:GetObject permission; ensure Account B's roles have s3:GetObject in their identity policies

Option A is correct because it uses an S3 bucket policy with a Principal set to Account B's account ID, which grants cross-account access to all IAM principals (users and roles) in Account B. Account B's IAM roles must also have an identity policy that allows s3:GetObject, ensuring that the effective permissions require both the bucket policy and the role's policy to allow the action. This approach avoids creating IAM users, sharing access keys, or setting up a role in Account A for Account B to assume.

Key principle: S3 bucket policy

Answer analysis

Option-by-option breakdown

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

  • Add an S3 bucket policy on Account A's bucket with Principal set to Account B's account ID and s3:GetObject permission; ensure Account B's roles have s3:GetObject in their identity policies

    Why this is correct

    Cross-account S3 access requires both a resource-based policy (bucket policy) that grants Account B access, and identity-based policies in Account B that allow the action. The bucket policy's Principal field specifies Account B's account root ARN or specific role ARNs. When both sides allow, the call succeeds without any role chaining or credential sharing.

    Related concept

    S3 bucket policy

  • Create an IAM role in Account A with s3:GetObject permission and a trust policy allowing Account B's roles to assume it

    Why it's wrong here

    This approach works (role chaining) but requires Account B's services to call sts:AssumeRole before each S3 operation, adding latency and complexity. The question asks for access without requiring Account B to assume a role in Account A.

  • Generate a presigned URL for each object in Account A and share the URLs with Account B's services

    Why it's wrong here

    Presigned URLs expire and must be regenerated regularly. They are appropriate for temporary, unauthenticated object access (e.g., browser downloads) but are not suitable for an ongoing programmatic access pattern where Account B's services read many objects on demand.

  • Enable S3 Access Points on the bucket and create an access point that allows Account B's VPC to connect via PrivateLink

    Why it's wrong here

    S3 Access Points simplify access management for large shared datasets and can restrict access to specific VPCs. However, cross-account access through an access point still requires a bucket policy delegation to the access point and a VPC endpoint setup — more configuration than a direct bucket policy grant, and PrivateLink is not strictly required for cross-account S3 access.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The SOA-C02 exam often tests the misconception that a bucket policy with a cross-account Principal automatically grants access to all IAM roles in that account, but candidates forget that the roles must also have an explicit allow in their identity policies for the action to succeed.

Detailed technical explanation

How to think about this question

When using a bucket policy with a cross-account Principal, AWS evaluates both the bucket policy and the requesting principal's identity policy; the request is allowed only if both policies grant the action (unless the bucket policy explicitly allows the account's root principal). This is an example of the 'intersection' model for cross-account S3 access, where the bucket policy must specify the external account ID (not an IAM role ARN) to grant access to all IAM principals in that account. In practice, this is commonly used for shared data lakes where multiple accounts need read access to a central bucket without managing roles or keys.

KKey Concepts to Remember

  • S3 bucket policy
  • cross-account access
  • Principal account ID
  • resource-based policy

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

S3 bucket policy

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.

Quick reference

AWS S3 Storage Class Comparison

Storage ClassMin DurationRetrievalUse Case
S3 StandardNoneImmediateFrequently accessed data
S3 Standard-IA30 daysImmediateInfrequent access, rapid retrieval
S3 One Zone-IA30 daysImmediateNon-critical infrequent data
S3 Intelligent-TieringNoneImmediate–hoursUnknown or changing access patterns
S3 Glacier Instant90 daysMillisecondsArchive with instant retrieval
S3 Glacier Flexible90 daysMinutes–hoursArchive, flexible retrieval
S3 Glacier Deep Archive180 daysHoursLong-term compliance archive

What to study next

Got this wrong? Here's your next step.

Review s3 bucket policy, then practise related SOA-C02 questions on the same topic to reinforce the concept.

Related practice questions

Related SOA-C02 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free SOA-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 SOA-C02 question test?

Security and Compliance — This question tests Security and Compliance — S3 bucket policy.

What is the correct answer to this question?

The correct answer is: Add an S3 bucket policy on Account A's bucket with Principal set to Account B's account ID and s3:GetObject permission; ensure Account B's roles have s3:GetObject in their identity policies — Option A is correct because it uses an S3 bucket policy with a Principal set to Account B's account ID, which grants cross-account access to all IAM principals (users and roles) in Account B. Account B's IAM roles must also have an identity policy that allows s3:GetObject, ensuring that the effective permissions require both the bucket policy and the role's policy to allow the action. This approach avoids creating IAM users, sharing access keys, or setting up a role in Account A for Account B to assume.

What should I do if I get this SOA-C02 question wrong?

Review s3 bucket policy, then practise related SOA-C02 questions on the same topic to reinforce the concept.

What is the key concept behind this question?

S3 bucket policy

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 →

How Courseiva writes practice questions · Editorial policy

Keep practising

More SOA-C02 practice questions

Last reviewed: Jun 11, 2026

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.

Loading comments…

Sign in to join the discussion.

This SOA-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 SOA-C02 exam.