S3 bucket should not allow put or restore actions from all principals

Misconfigured S3 buckets can leak private information to the entire internet or allow unauthorized data tampering / deletion. S3 bucket policy should ensure that principal of least privilege is being followed. A condition statement can be used to control the scope of the policy.

Risk Level: High
Cloud Entity: Simple Storage Service (S3)
CloudGuard Rule ID: D9.AWS.IAM.95
Covered by Spectral: Yes
Category: Storage


S3Bucket should not have policy.Statement with [Effect='Allow' and (Principal='*' or Principal.AWS='*') and Condition and ( (Action contain [$ regexMatch /^s3:Put/] or Action regexMatch /^s3:Put/) or (Action contain [$ = 's3:RestoreObject'] or Action = 's3:RestoreObject') )]


From Portal:

  1. Sign in to the AWS Management Console and open the Amazon S3 console at https://console.aws.amazon.com/s3/.
  2. In the Buckets list, choose the name of the bucket that you want to create a bucket policy for or whose bucket policy you want to edit.
  3. Choose Permissions.
  4. Under Bucket policy, choose Edit. This opens the Edit bucket policy page.
  5. On the Edit bucket policy page, explore Policy examples in the Amazon S3 User Guide, choose Policy generator to generate a policy automatically, or edit the JSON in the Policy section.
    Here verify policies for s3:Put or s3:RestoreObject actions for principals ''. If necessary, modify the policy instead, to limit the access to specific principals.
  6. In the Policy box, edit the existing policy or paste the bucket policy from the Policy generator. Make sure to resolve security warnings, errors, general warnings, and suggestions before you save your policy.
  7. Choose Save changes, which returns you to the Bucket Permissions page.

From TF:
Add a policy document with required permissions and appropriate condition as needed as follows:

data "aws_iam_policy_document" "example" {
	statement {
		effect = "Allow"
		actions = [
		principals {
		resources = [
		condition {
			test     = TEST
			variable = CONTEXT_VARIABLE
			values = [

From Command Line:
To add a policy with required permissions and appropriate condition as needed, run:

aws s3api put-bucket-policy --bucket BUCKET-NAME --policy file://policy.json


  1. https://docs.aws.amazon.com/cli/latest/reference/s3api/put-bucket-policy.html
  2. https://registry.terraform.io/providers/hashicorp/aws/3.3.0/docs/data-sources/iam_policy_document
  3. https://docs.aws.amazon.com/AmazonS3/latest/userguide/example-bucket-policies.html
  4. https://docs.aws.amazon.com/AmazonS3/latest/dev/using-iam-policies.html

Simple Storage Service (S3)

Companies today need the ability to simply and securely collect, store, and analyze their data at a massive scale. Amazon S3 is object storage built to store and retrieve any amount of data from anywhere ��� web sites and mobile apps, corporate applications, and data from IoT sensors or devices. It is designed to deliver 99.999999999% durability, and stores data for millions of applications used by market leaders in every indu

Compliance Frameworks

  • AWS CCPA Framework
  • AWS CloudGuard Best Practices
  • AWS CloudGuard S3 Bucket Security
  • AWS CloudGuard SOC2 based on AICPA TSC 2017
  • AWS CloudGuard Well Architected Framework
  • AWS ISO 27001:2013
  • AWS ITSG-33
  • AWS LGPD regulation
  • AWS MAS TRM Framework
  • AWS MITRE ATT&CK Framework v10
  • AWS MITRE ATT&CK Framework v11
  • AWS NIST 800-171
  • AWS NIST 800-53 Rev 4
  • AWS NIST 800-53 Rev 5
  • AWS NIST CSF v1.1
  • AWS PCI-DSS 3.2
  • AWS Risk Management
  • AWS Security Risk Management