Question 427 of 1,738
Identity and Access ManagementhardMultiple SelectObjective-mapped

Quick Answer

The answer is to generate a pre-signed URL for each log file and use AWS Security Token Service (STS) to issue temporary credentials. These two actions together provide the most secure way to grant temporary S3 access to an external auditor without an AWS account because they both enforce a limited time window and require no permanent identity or sign-up from the auditor. A pre-signed URL embeds credentials directly into the URL for single-object read-only access, while STS issues a temporary access key, secret key, and session token that the auditor can use to authenticate API requests to the bucket. On the AWS Certified Security Specialty SCS-C02 exam, this scenario tests your understanding of identity federation and time-bound access controls, with a common trap being to suggest creating an IAM user or sharing long-term keys. Remember the mnemonic “URL for one, STS for many” — pre-signed URLs are ideal for individual files, while STS handles broader bucket access.

SCS-C02 Identity and Access Management Practice Question

This SCS-C02 practice question tests your understanding of identity and access management. 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 security engineer is designing a solution to allow an external auditor to access logs in an S3 bucket in the company's AWS account. The auditor does not have an AWS account. The engineer needs to grant read-only access to the specific bucket for a limited time. Which TWO actions should the engineer take? (Choose two.)

Question 1hardmulti select
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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

Use AWS STS to issue temporary credentials that the auditor can use to access the bucket.

Option C is correct because AWS Security Token Service (STS) can issue temporary, limited-privilege credentials (access key, secret key, and session token) that the auditor can use to authenticate API requests to the S3 bucket. This approach does not require the auditor to have an AWS account and allows the engineer to control the validity period (via the DurationSeconds parameter) to enforce a limited time window. Option D is correct because a pre-signed URL embeds temporary credentials and a specific expiration time, granting read-only access to a single object without requiring the auditor to have AWS credentials or an AWS account.

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.

  • Enable S3 Access Analyzer on the bucket to generate findings for the auditor.

    Why it's wrong here

    Access Analyzer only identifies potential access issues; it does not grant access.

  • Create a cross-account IAM role in the company's account and share the role ARN with the auditor.

    Why it's wrong here

    The auditor does not have an AWS account to assume the role.

  • Use AWS STS to issue temporary credentials that the auditor can use to access the bucket.

    Why this is correct

    STS can issue temporary credentials with a specified expiration; the auditor can use these to access the bucket.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Generate a pre-signed URL for each log file the auditor needs to access.

    Why this is correct

    Pre-signed URLs provide time-limited access to specific objects without requiring AWS credentials.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Configure the bucket policy to grant access to 'Principal': '*' with a condition that limits access to the auditor's IP address.

    Why it's wrong here

    This would make the bucket public; not recommended for sensitive logs.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often choose cross-account IAM roles (Option B) without realizing that the external user must have an AWS account to assume the role, which is explicitly not the case in this scenario.

Detailed technical explanation

How to think about this question

Pre-signed URLs are generated using the AWS Signature Version 4 signing process, where the engineer signs a URL with their own IAM credentials and specifies an expiration time (up to 7 days by default, configurable via the ExpiresIn parameter). The auditor can use the pre-signed URL with any HTTP client (e.g., curl, browser) to perform a GET request without needing AWS credentials. For STS temporary credentials, the engineer calls AssumeRole (or GetFederationToken) to obtain credentials with a configurable expiration (up to 12 hours for IAM roles, up to 36 hours for federation tokens), which are then securely shared with the auditor for programmatic access via the AWS CLI or SDK.

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 SCS-C02 practice-question pages

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

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FAQ

Questions learners often ask

What does this SCS-C02 question test?

Identity and Access Management — This question tests Identity and Access Management — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Use AWS STS to issue temporary credentials that the auditor can use to access the bucket. — Option C is correct because AWS Security Token Service (STS) can issue temporary, limited-privilege credentials (access key, secret key, and session token) that the auditor can use to authenticate API requests to the S3 bucket. This approach does not require the auditor to have an AWS account and allows the engineer to control the validity period (via the DurationSeconds parameter) to enforce a limited time window. Option D is correct because a pre-signed URL embeds temporary credentials and a specific expiration time, granting read-only access to a single object without requiring the auditor to have AWS credentials or an AWS account.

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

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Same concept, more angles

1 more ways this is tested on SCS-C02

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. A company needs to allow an external auditor to access a specific S3 bucket for 30 days. The auditor does not have an AWS account. What is the MOST secure way to grant temporary access?

medium
  • A.Create an IAM user with long-term credentials and share them with the auditor.
  • B.Use AWS STS to issue temporary credentials via a custom identity broker.
  • C.Grant access via a bucket policy using the auditor's email address as a condition.
  • D.Create an IAM role and allow the auditor to assume it using SAML federation.

Why B: Option C is correct because you can create a role with a trust policy that allows the external auditor to assume it, and the auditor authenticates using their own credentials? But the auditor has no AWS account, so they cannot assume a role directly. The correct answer is to use a bucket policy granting access to a role that the auditor can assume via web identity federation? Actually, Option D is correct: Use STS temporary credentials with a custom federation broker. However, Option A is not secure. Option B is not possible without AWS account. Option C is not possible without trust. Option D is the best: you can create a federation proxy that authenticates the auditor and issues temporary credentials. Wait, let's reconsider. The correct answer is Option D: Use AWS STS to generate temporary credentials for the auditor after authenticating them via a custom identity broker. This is the recommended approach for granting access to external users without AWS accounts.

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Last reviewed: Jun 11, 2026

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This SCS-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 SCS-C02 exam.