Courseiva
← SAA-C03
Full test
Question 33 of 1,040
Design Secure Architectures →easyMultiple ChoiceObjective-mapped

Quick Answer

The answer is that Account B’s calling principal must have an identity-based policy allowing sts:AssumeRole on RoleInAccountA’s ARN. This is required because cross-account role assumption is a two-way permission: the trust policy in Account A grants the target role’s trust to the external principal, but the calling principal in Account B still needs its own explicit identity-based policy to initiate the sts:AssumeRole API call. Without that policy, AWS applies an implicit deny, resulting in the AccessDenied error even if Account A’s trust policy is perfectly configured. On the SAA-C03 exam, this scenario tests your understanding that both sides of the cross-account relationship must grant permission—a common trap is assuming the trust policy alone suffices. Remember the “two keys” rule: the trust policy unlocks the door from the target account, but the caller’s identity policy must turn the key to enter. A helpful mnemonic is “Trust lets you in, but your own policy lets you knock.”

SAA-C03 Design Secure Architectures Practice Question

This SAA-C03 practice question tests your understanding of design secure architectures. 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. 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.

Account A hosts an IAM role (RoleInAccountA). The trust policy in Account A correctly allows a specific principal from Account B to call sts:AssumeRole. However, when Account B’s application calls sts:AssumeRole, it receives an AccessDenied error. What is the most likely missing requirement in Account B?

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.

Question 1easymultiple choice
Full question →

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

✓

Account B’s calling principal must have an identity-based policy that allows sts:AssumeRole on RoleInAccountA’s role ARN.

Option A is correct because for an IAM role in Account A to be assumed by a principal in Account B, two conditions must be met: (1) the trust policy of the role in Account A must grant the sts:AssumeRole permission to the Account B principal, and (2) the calling principal in Account B must have an identity-based policy that explicitly allows sts:AssumeRole on the ARN of RoleInAccountA. Without this identity-based policy in Account B, the request is denied by AWS's explicit deny default, even if the trust policy in Account A is correctly configured.

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.

  • ✓

    Account B’s calling principal must have an identity-based policy that allows sts:AssumeRole on RoleInAccountA’s role ARN.

    Why this is correct

    Cross-account role assumption is authorized on both sides: the trust policy allows who can assume, and the caller’s identity policy must allow sts:AssumeRole on the target role ARN.

    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.

  • ✗

    Account A must attach an S3 bucket policy statement to allow sts:AssumeRole from Account B.

    Why it's wrong here

    S3 bucket policies do not control STS AssumeRole. STS authorization is evaluated using the target role’s trust policy and the caller’s identity-based permissions (plus any applicable permissions boundaries/SCPs).

  • ✗

    Account B must add kms:Decrypt permissions to the caller to satisfy AssumeRole.

    Why it's wrong here

    kms:Decrypt is only relevant when decrypting KMS-encrypted data. AssumeRole authorization does not require KMS decrypt permissions.

  • ✗

    Account B must create an SCP in the organization to allow sts:AssumeRole.

    Why it's wrong here

    SCPs can restrict allowed actions, but if a trust policy is already correct, the most common reason for AccessDenied is missing identity-based sts:AssumeRole permissions in Account B. SCPs typically produce explicit denies when they block an action, not the standard missing-permission scenario described here.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often assume the trust policy alone is sufficient for cross-account role assumption, forgetting that the calling principal must also have an explicit identity-based policy granting sts:AssumeRole on the target role ARN.

Trap categories for this question

  • Scenario analysis trap

    SCPs can restrict allowed actions, but if a trust policy is already correct, the most common reason for AccessDenied is missing identity-based sts:AssumeRole permissions in Account B. SCPs typically produce explicit denies when they block an action, not the standard missing-permission scenario described here.

Detailed technical explanation

How to think about this question

When sts:AssumeRole is called, AWS evaluates both the trust policy of the target role (resource-based policy) and the identity-based policy of the calling principal. The trust policy defines which principals are allowed to assume the role, but the caller must also have explicit permission via an identity-based policy (e.g., an IAM user or role policy) that allows the sts:AssumeRole action on the specific role ARN. This dual-authorization model prevents unauthorized cross-account access even if the trust policy is open. In practice, the caller's policy typically uses a statement like: {"Effect":"Allow","Action":"sts:AssumeRole","Resource":"arn:aws:iam::AccountA:role/RoleInAccountA"}.

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.

Related practice questions

Related SAA-C03 practice-question pages

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

Design Secure Architectures practice questions

Practise SAA-C03 questions linked to Design Secure Architectures.

Design Resilient Architectures practice questions

Practise SAA-C03 questions linked to Design Resilient Architectures.

Design High-Performing Architectures practice questions

Practise SAA-C03 questions linked to Design High-Performing Architectures.

Design Cost-Optimized Architectures practice questions

Practise SAA-C03 questions linked to Design Cost-Optimized Architectures.

SAA-C03 VPC practice questions

Practise SAA-C03 questions linked to SAA-C03 VPC.

SAA-C03 S3 lifecycle policy questions

Practise SAA-C03 questions linked to SAA-C03 S3 lifecycle policy questions.

SAA-C03 RDS Multi-AZ questions

Practise SAA-C03 questions linked to SAA-C03 RDS Multi-AZ questions.

SAA-C03 IAM policy practice questions

Practise SAA-C03 questions linked to SAA-C03 IAM policy.

SAA-C03 Route 53 failover questions

Practise SAA-C03 questions linked to SAA-C03 Route 53 failover questions.

SAA-C03 CloudFront practice questions

Practise SAA-C03 questions linked to SAA-C03 CloudFront.

SAA-C03 NAT gateway questions

Practise SAA-C03 questions linked to SAA-C03 NAT gateway questions.

SAA-C03 VPC endpoint questions

Practise SAA-C03 questions linked to SAA-C03 VPC endpoint questions.

Practice this exam

Start a free SAA-C03 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions20 questions30 questions50 questionsTimed 30
SAA-C03 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this SAA-C03 question test?

Design Secure Architectures — This question tests Design Secure Architectures — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Account B’s calling principal must have an identity-based policy that allows sts:AssumeRole on RoleInAccountA’s role ARN. — Option A is correct because for an IAM role in Account A to be assumed by a principal in Account B, two conditions must be met: (1) the trust policy of the role in Account A must grant the sts:AssumeRole permission to the Account B principal, and (2) the calling principal in Account B must have an identity-based policy that explicitly allows sts:AssumeRole on the ARN of RoleInAccountA. Without this identity-based policy in Account B, the request is denied by AWS's explicit deny default, even if the trust policy in Account A is correctly configured.

What should I do if I get this SAA-C03 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 →

How Courseiva writes practice questions · Editorial policy

Keep practising

More SAA-C03 practice questions

Browse all SAA-C03 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 SAA-C03 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 SAA-C03 exam.