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Howiecamp
Asked: 2017-04-10 10:15:04 +0800 CST

Amazon S3 permissions don't specify public access however public can read objects

  • 772

I've got an AWS S3 bucket where the only permissions I've defined are for myself and Amazon's Log Delivery. As shown from the AWS Console:

aws s3 bucket perms 1

As shown from another tool (S3 Browser):

aws s3 bucket perms 2

There's no public or everyone or anonymous users in the ACL.

Yet, public/anonymous users can read objects from the bucket:

public access

How can this be?

amazon-web-services

1 Answers

  1. Best Answer

    S3 has three ways to control access:

    • IAM
    • Bucket Policy
    • ACLs

    I suspect you have a bucket policy that provides public access.

    A bucket policy like this, which you haven't mentioned, would provide public access.

    {
  "Version": "2012-10-17",
  "Statement": [
      {
          "Sid": "AddPerm",
          "Effect": "Allow",
          "Principal": "*",
          "Action": "s3:GetObject",
          "Resource": "arn:aws:s3:::BUCKETNAME/*"
      }
  ]
}
    • 8