← SAA-C03·Amazon Web Services

Question 618 of 1,040

Design Secure Architectures →mediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is to add a `Bool` condition with `"aws:MultiFactorAuthPresent": "true"` to the role trust policy for the `sts:AssumeRole` action. This condition key evaluates whether the requesting principal’s session was established using multi-factor authentication; when set to `"true"`, it ensures that only STS sessions created after a successful MFA challenge can assume the cross-account role. On the SAA-C03 exam, this tests your understanding of how to enforce MFA for cross-account role assumption using IAM policy conditions, often appearing as a scenario where a simple trust policy must be hardened without breaking existing access. A common trap is confusing `aws:MultiFactorAuthPresent` with `aws:SourceIdentity` or using a `StringEquals` condition instead of `Bool`, which would not work because the key returns a boolean value. Memory tip: think “MFA must be present, so set the Bool to true” — if MFA is absent, the condition fails and the role cannot be assumed.

SAA-C03 Design Secure Architectures Practice Question

This SAA-C03 practice question tests your understanding of design secure architectures. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 Y provides a role named AnalyticsReadOnly to engineers in Account X. The role trust policy currently allows sts:AssumeRole from the Account X principal. A new security requirement states that only STS sessions created with MFA are allowed to assume the role. Which trust policy condition is the best choice to enforce MFA for sts:AssumeRole?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

Question 1mediummultiple choice

Full question →

A
Add a condition "Bool": { "aws:MultiFactorAuthPresent": "true" } in the role trust policy for the sts:AssumeRole action.
aws:MultiFactorAuthPresent is a condition key designed to reflect whether MFA was used when establishing the STS session. By requiring it to be true in the trust policy, STS denies AssumeRole when the caller did not authenticate with MFA.
B
Add a condition "StringEquals": { "aws:username": "mfa-user" } in the IAM policy attached to the role.
Why wrong: Conditions on aws:username in the role’s attached identity policy do not control the trust decision. The trust policy is what authorizes (or denies) AssumeRole; identity-policy username conditions are not a reliable gate for who can establish the STS session.
C
Add a condition requiring "sts:ExternalId" to equal a fixed value in the trust policy.
Why wrong: ExternalId helps mitigate the confused-deputy problem, but it does not prove that MFA was used to create the STS session. The MFA requirement is about authentication strength, not about ExternalId values.
D
Add a condition "Bool": { "aws:SecureTransport": "true" } in the trust policy to require HTTPS.
Why wrong: aws:SecureTransport is about using HTTPS/TLS, which is unrelated to whether MFA occurred. A request can be over HTTPS without MFA authentication, so this does not satisfy the requirement.

Full breakdown with real-world context →

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 a condition "Bool": { "aws:MultiFactorAuthPresent": "true" } in the role trust policy for the sts:AssumeRole action.

Option A is correct because the `aws:MultiFactorAuthPresent` condition key checks whether the principal used MFA to obtain the session credentials. By adding a `Bool` condition set to `"true"` in the trust policy for the `sts:AssumeRole` action, only STS sessions that were created after MFA authentication will be allowed to assume the role. This directly enforces the security requirement without affecting other authentication methods.

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.

✓
Add a condition "Bool": { "aws:MultiFactorAuthPresent": "true" } in the role trust policy for the sts:AssumeRole action.
Why this is correct
aws:MultiFactorAuthPresent is a condition key designed to reflect whether MFA was used when establishing the STS session. By requiring it to be true in the trust policy, STS denies AssumeRole when the caller did not authenticate with MFA.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Add a condition "StringEquals": { "aws:username": "mfa-user" } in the IAM policy attached to the role.
Why it's wrong here
Conditions on aws:username in the role’s attached identity policy do not control the trust decision. The trust policy is what authorizes (or denies) AssumeRole; identity-policy username conditions are not a reliable gate for who can establish the STS session.
✗
Add a condition requiring "sts:ExternalId" to equal a fixed value in the trust policy.
Why it's wrong here
ExternalId helps mitigate the confused-deputy problem, but it does not prove that MFA was used to create the STS session. The MFA requirement is about authentication strength, not about ExternalId values.
✗
Add a condition "Bool": { "aws:SecureTransport": "true" } in the trust policy to require HTTPS.
Why it's wrong here
aws:SecureTransport is about using HTTPS/TLS, which is unrelated to whether MFA occurred. A request can be over HTTPS without MFA authentication, so this does not satisfy the requirement.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates may confuse `aws:MultiFactorAuthPresent` with other condition keys like `aws:SecureTransport` or `aws:username`, or think that `sts:ExternalId` can enforce MFA, when in fact only the `Bool` condition on `aws:MultiFactorAuthPresent` directly checks MFA status.

Trap categories for this question

Similar concept trap
ExternalId helps mitigate the confused-deputy problem, but it does not prove that MFA was used to create the STS session. The MFA requirement is about authentication strength, not about ExternalId values.

Detailed technical explanation

How to think about this question

The `aws:MultiFactorAuthPresent` condition key evaluates to `true` only when the session credentials were obtained via an MFA-authenticated sign-in (e.g., using a virtual or hardware MFA device). This key is available for all AWS API calls, including `sts:AssumeRole`, and is evaluated at the time the session is created. A common subtlety is that if the role is assumed by a service or script that does not pass MFA, the condition will deny access, ensuring that only human engineers who authenticate with MFA can use the role.

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 company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.

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 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 questions 20 questions 30 questions 50 questions Timed 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: Add a condition "Bool": { "aws:MultiFactorAuthPresent": "true" } in the role trust policy for the sts:AssumeRole action. — Option A is correct because the `aws:MultiFactorAuthPresent` condition key checks whether the principal used MFA to obtain the session credentials. By adding a `Bool` condition set to `"true"` in the trust policy for the `sts:AssumeRole` action, only STS sessions that were created after MFA authentication will be allowed to assume the role. This directly enforces the security requirement without affecting other authentication methods.

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: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

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

Same concept, more angles

1 more ways this is tested on SAA-C03

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. Account A hosts an IAM role that Account B developers must assume for a limited task. You want to require MFA for anyone assuming the role. Which trust policy condition most directly enforces that requirement for sts:AssumeRole?

easy

✓ A.Add a statement condition requiring "Bool": {"aws:MultiFactorAuthPresent": "true"} in the role trust policy.
B.Add a condition requiring "StringEquals": {"aws:PrincipalOrgID": "o-example"} without any MFA condition.
C.Add a statement that denies sts:AssumeRole when the requested role session name contains the text "dev".
D.Require HTTPS by setting a condition on "aws:SecureTransport": "true" in the trust policy.

Why A: Option A is correct because the `aws:MultiFactorAuthPresent` condition key in the role trust policy directly checks whether the caller authenticated with a valid MFA device before calling `sts:AssumeRole`. When set to "true" with a Bool condition, it enforces that the session must have been established after MFA verification, which is the most direct and standard way to require MFA for role assumption.

Keep practising

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…

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.