The “Access Denied” error for ListObjectsV2 operations in an S3 bucket typically occurs when the IAM user or role attempting to perform the operation does not have the necessary permissions. Resolving this issue involves adjusting the IAM policies to grant the required permissions.
Here’s how you can resolve it:

Identify the IAM User or Role: Determine which IAM entity is attempting to perform the ListObjectsV2 operation.

Ensure permission for ListObjectsV2: Make sure that the policy includes permissions for the s3:ListBucket action, which allows listing the objects within the bucket. Specifically, you need to ensure that the policy allows the s3:ListBucket action on the specific bucket or a wildcard (*) for all buckets.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "s3:ListBucket",
            "Resource": "arn:aws:s3:::your-bucket-name"
        },
        {
            "Effect": "Allow",
            "Action": [
                "s3:GetObject",
                "s3:PutObject",
                "s3:DeleteObject"
            ],
            "Resource": "arn:aws:s3:::your-bucket-name/*"
        }
    ]
}

Example policy for All Bucket:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:ListBucket",
                "s3:ListBucketVersions"
            ],
            "Resource": "arn:aws:s3:::your-bucket-name"
        },
        {
            "Effect": "Allow",
            "Action": "s3:ListAllMyBuckets",
            "Resource": "*"
        }
    ]
}

Replace “your-bucket-name” with the name of your S3 bucket.

Attach Policy: Once you have the policy, attach it to the IAM user or role that needs the permissions.

Test: After updating the policies, test the ListObjectsV2 operation again to ensure that the error is resolved.

Review and refine permissions: Ensure that the permissions granted are appropriate for the tasks the IAM entity needs to perform. Avoid granting more permissions than necessary for security reasons.

By following these steps and ensuring that the IAM policies are correctly configured, you should be able to resolve the “Access Denied” error for ListObjectsV2 operations in your S3 bucket.