SAA-C03 Design Resilient Architectures Practice Question
Exhibit
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "s3:GetObject",
"Resource": "arn:aws:s3:::my-backup-bucket/*"
}
]
}Refer to the exhibit. The current IAM policy allows an EC2 instance to read backups. The architect wants to ensure the data is recoverable if the source bucket is compromised by an external actor with write access. What should be done?
⚠ Common exam trap
SAA-C03 often tests whether candidates know that Object Lock provides WORM immutability even against administrators, and candidates mistakenly pick encryption or IAM policies as deletion protection.
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
✓
Enable S3 Object Lock on the bucket.
S3 Object Lock enforces a Write Once Read Many (WORM) model, preventing objects from being deleted or overwritten for a specified retention period — even by users with full administrative permissions. This directly addresses the scenario where an external actor with write access could otherwise overwrite or delete backups, ensuring the data remains recoverable. Object Lock requires versioning to be enabled on the bucket.
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 Object Lock on the bucket.
Why this is correct
Object Lock provides WORM (Write Once, Read Many) protection. By preventing objects from being overwritten or deleted for a set period, it ensures that even an account compromise cannot destroy the backup data. This is the most effective way to secure backups against malicious actors and accidental data loss.
- ✗
Apply a Bucket Policy to deny s3:PutObject for all users.
Why it's wrong here
Applying a permanent Deny on PutObject would prevent the application from ever updating the backups. While this prevents unauthorized modifications, it also breaks the functionality of the backup process itself. Object Lock is a more granular and effective control that allows writes but prevents deletions and overwrites.
- ✗
Create a read-only IAM user for the EC2 instance.
Why it's wrong here
The EC2 instance already has read access. Adding an IAM user does not solve the underlying risk of the source bucket being compromised. The problem is about protecting the bucket's content, not limiting the permissions of the client that is consuming the backups for recovery.
- ✗
Enable S3 Server-Side Encryption (SSE-S3).
Why it's wrong here
Encryption protects data at rest from being read by unauthorized parties. It does not prevent a malicious actor with write permissions from deleting or overwriting the objects. Resilience against data compromise requires features that prevent deletion and modification, such as Object Lock, not just encryption of the data.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
About these practice questions
This SAA-C03 question is part of Courseiva's 149-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
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.