DEA-C01 Data Operations and Support Practice Question

Exhibit

IAM policy attached to an IAM role used by AWS Glue:
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "s3:GetObject",
        "s3:PutObject"
      ],
      "Resource": "arn:aws:s3:::my-bucket/*"
    },
    {
      "Effect": "Allow",
      "Action": [
        "s3:ListBucket"
      ],
      "Resource": "arn:aws:s3:::my-bucket"
    },
    {
      "Effect": "Allow",
      "Action": [
        "glue:Get*",
        "glue:BatchGet*"
      ],
      "Resource": "*"
    }
  ]
}

A data engineer is troubleshooting an AWS Glue ETL job that fails with an 'Access Denied' error when trying to write to an S3 bucket. The IAM role used by the job has the policy shown in the exhibit. The bucket 'my-bucket' uses S3 default encryption with AWS KMS. What is the most likely missing permission?

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

✓

kms:GenerateDataKey and kms:Decrypt

When an S3 bucket uses AWS KMS for default encryption, any write operation requires the IAM role to have kms:GenerateDataKey and kms:Decrypt permissions on the KMS key. The policy in the exhibit grants s3:PutObject but does not include any KMS actions, resulting in an 'Access Denied' error. Option A (s3:GetObjectVersion) is not needed for writing. Option B (glue:GetObject) is not a valid AWS action. Option C (s3:ListBucketMultipartUploads) is not required for a write operation. Option D (s3:PutObjectAcl) is unnecessary unless the job explicitly sets ACLs.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
s3:GetObjectVersion
Why it's wrong here
The job fails on write, so s3:PutObject is missing; s3:GetObjectVersion only permits reading a specific object version and grants no write capability. It is tempting because versioned buckets do require version-level read permissions for source data, but this bucket's failure is a write denied by the IAM policy and KMS key policy.
✗
glue:GetObject
Why it's wrong here
Writing to S3 requires s3:PutObject, not glue:GetObject; the glue: prefix covers Data Catalog operations, so it grants no S3 data-plane access at all. It is tempting because Glue jobs do read source objects, but reading is not the failing operation here, and the write also needs kms:GenerateDataKey for the KMS-encrypted bucket.
✗
s3:ListBucketMultipartUploads
Why it's wrong here
ListBucketMultipartUploads only enumerates in-progress multipart uploads; it grants no write capability and no KMS access. It is tempting because Glue writes large objects via multipart uploads, and it would be correct when a job must resume or abort an interrupted multipart upload rather than write encrypted objects.
✗
s3:PutObjectAcl
Why it's wrong here
PutObjectAcl sets object ACLs, which are irrelevant under bucket-owner-enforced ownership and grant no KMS permission. It is tempting because ACL-related denials are common, and it would be correct when a job must apply a canned ACL, not when KMS denies GenerateDataKey for the default encryption.
✓
kms:GenerateDataKey and kms:Decrypt
Why this is correct
Writing to an SSE-KMS encrypted bucket requires the role to call KMS GenerateDataKey to obtain a data key for encrypting each object, plus Decrypt for reads and multipart uploads. The IAM policy grants only S3 actions, so the missing kms:GenerateDataKey and kms:Decrypt permissions cause the Access Denied.

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

DEA-C01 Data Operations and Support Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

Related to this question