hardMultiple ChoiceObjective-mapped

CCSP Practice Question: A security architect applies the above bucket…

Exhibit

Refer to the exhibit.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Deny",
      "Principal": "*",
      "Action": "s3:PutObject",
      "Resource": "arn:aws:s3:::example-bucket/*",
      "Condition": {
        "Null": {
          "s3:x-amz-server-side-encryption": "true"
        }
      }
    }
  ]
}

A security architect applies the above bucket policy to an Amazon S3 bucket containing sensitive data. What is the net effect of this policy?

⚠ Common exam trap

ISC2 often tests the distinction between SSE-S3 (`AES256`) and SSE-KMS (`aws:kms`) in bucket policy conditions, leading candidates to confuse the required header value and incorrectly select an option involving KMS.

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

✓

It denies all PutObject requests that do not specify an encryption header, enforcing encryption at rest.

The bucket policy uses a condition key `s3:x-amz-server-side-encryption` with a `StringNotEquals` condition to deny `PutObject` requests that do not include the `x-amz-server-side-encryption` header set to `AES256`. This effectively denies any upload that does not specify server-side encryption with S3-Managed Keys (SSE-S3), enforcing encryption at rest for all objects written to 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.

✗
It denies all PutObject requests, regardless of encryption.
Why it's wrong here
Incorrect: The policy only denies when the encryption header is missing; if present, the deny condition is not met.
✓
It denies all PutObject requests that do not specify an encryption header, enforcing encryption at rest.
Why this is correct
Correct: The Deny with Null condition blocks requests where the encryption header is null (missing), thus requiring encryption.
✗
It allows only PutObject requests using SSE-KMS (AWS KMS managed keys).
Why it's wrong here
Incorrect: The policy does not specify a particular encryption type; it only requires any encryption header.
✗
It allows PutObject requests only from principals that use an IAM role with encryption permissions.
Why it's wrong here
Incorrect: The policy does not reference IAM roles; it is a bucket policy that evaluates the encryption header.

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

Go deeper

CCSP Practice Question: A security architect applies the above bucket…

Exhibit

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

Related to this question