The answer is to create an S3 bucket policy that grants the CloudTrail service principal write access, with a condition checking the source account ID. This is the most secure approach because it explicitly restricts log delivery to only CloudTrail from your specified AWS accounts, preventing any unauthorized service or account from writing to the central bucket. On the AWS Certified Security Specialty SCS-C02 exam, this concept tests your understanding of cross-account CloudTrail log delivery bucket policy design, where a common trap is choosing a policy without the source account condition—that would allow any CloudTrail in any account to deliver logs, breaking security boundaries. Remember that CloudTrail uses the service principal, not IAM roles, for cross-account writes, and KMS encryption alone does not control write permissions. Memory tip: think "Service Principal + Source Account = Secure Cross-Account Delivery."
SCS-C02 Security Logging and Monitoring Practice Question
This SCS-C02 practice question tests your understanding of security logging and monitoring. 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.
A company wants to centralize CloudTrail logs from multiple AWS accounts into a single S3 bucket for security analysis. The logs must be encrypted at rest and access must be logged. What is the MOST secure way to grant cross-account access to the central S3 bucket?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Create an S3 bucket policy that grants CloudTrail service principal permission to write objects, with a condition checking the source account ID.
Option A is correct because using a bucket policy with a condition for CloudTrail service principal and source account ensures only CloudTrail from allowed accounts can write. Option B is wrong because KMS encryption does not control write access. Option C is wrong because IAM roles are not used by CloudTrail for cross-account delivery. Option D is wrong because a bucket policy without account restriction would allow any CloudTrail to write.
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.
✗
Create an S3 bucket policy that grants s3:PutObject to everyone, and rely on CloudTrail to restrict access.
Why it's wrong here
A permissive bucket policy violates least privilege.
✗
Create an IAM role in the central account that each member account can assume to write logs.
Why it's wrong here
CloudTrail uses service principals, not IAM roles, for cross-account delivery.
✓
Create an S3 bucket policy that grants CloudTrail service principal permission to write objects, with a condition checking the source account ID.
Why this is correct
This restricts cross-account writes to only those accounts specified.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use an S3 bucket with default encryption enabled and share the KMS key with the other accounts.
Why it's wrong here
Encryption does not control write permissions.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
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.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→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 SCS-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Security Logging and Monitoring — This question tests Security Logging and Monitoring — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create an S3 bucket policy that grants CloudTrail service principal permission to write objects, with a condition checking the source account ID. — Option A is correct because using a bucket policy with a condition for CloudTrail service principal and source account ensures only CloudTrail from allowed accounts can write. Option B is wrong because KMS encryption does not control write access. Option C is wrong because IAM roles are not used by CloudTrail for cross-account delivery. Option D is wrong because a bucket policy without account restriction would allow any CloudTrail to write.
What should I do if I get this SCS-C02 question wrong?
Identify which SCS-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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 →
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 wants to centralize security logs from multiple AWS accounts into a single S3 bucket. The logging accounts (e.g., security, production) each have their own CloudTrail trails. Which configuration is required to allow cross-account log delivery?
easy
A.Create an IAM role in the destination account with write permissions and allow CloudTrail in source accounts to assume that role.
B.Use a customer-managed KMS key in the destination account and share it with the source accounts.
✓ C.Create an S3 bucket policy in the destination account that allows the CloudTrail service principal to write objects.
D.Configure S3 bucket ACLs to grant write access to the source account IDs.
Why C: Option A is correct because CloudTrail can deliver logs to an S3 bucket in another account by using a bucket policy that grants CloudTrail's service principal write access. Option B is wrong because KMS keys are for encryption, not cross-account access. Option C is wrong because S3 ACLs are not recommended for cross-account; bucket policy is used. Option D is wrong because IAM roles are used for other services but CloudTrail uses bucket policies.
Variation 2. A security engineer needs to centralize logs from multiple AWS accounts into a single S3 bucket. Which solution is most secure?
easy
A.Deliver logs to separate buckets per account and use S3 replication to copy them to a central bucket.
B.Use a single S3 bucket in the management account and have each account write logs directly without additional permissions.
✓ C.Configure each account's CloudTrail to deliver to a centralized S3 bucket in a logging account, with a bucket policy allowing CloudTrail from source accounts.
D.Stream logs to Amazon Kinesis Data Firehose in each account and consolidate into a single S3 bucket via cross-account delivery.
Why C: Option A is correct because using a centralized S3 bucket with a bucket policy that grants cross-account permissions from each source account's CloudTrail is a standard secure approach. Option B is incorrect because writing from one account to another requires explicit permissions, not automatic. Option C is incorrect because delivering to separate buckets then copying adds complexity and potential security gaps. Option D is incorrect because Kinesis Firehose can be used but is not required; S3 bucket policy is simpler and secure.
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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.
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