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Perform following to update S3 bucket access control list:
Login to the AWS Management Console at https://console.aws.amazon.com.
Navigate to s3 console.
In the navigation pane, select buckets.
Click on the bucket to be modified, click Permissions.
In the permissions pane, navigate to Public Access section.
The section shows a list of permissions assigned to everyone.
Uncheck all the permissions granted to everyone.
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