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lacework-global-138

Ensure the bucket ACL does not grant AWS users WRITE_ACP permission [modify bucket ACL]

Description

The S3 bucket ACL gives any authenticated AWS user permission to write [or re-write] the bucket ACL. It is best practice to restrict WRITE_ACP permission to only principals who require it.

Note: S3 buckets created with the default/recommended AWS settings have ACLs disabled and will therefore be compliant with this policy.

Remediation

Perform the following to revoke WRITE_ACP permission for all AWS users:

  1. Sign in to the AWS Management Console

  2. Select Services

  3. Select S3

  4. Select the bucket to change

  5. Navigate to Permissions

  6. Navigate to Access Control List and select Edit

  7. Against Authenticated users group (anyone with an AWS account), uncheck 'Write' under Bucket ACL

  8. Select Save changes

  9. Repeat steps 4-8 for each bucket requiring updated permissions