Ensure S3 Bucket Policy is set to deny HTTP requests

To protect data in transit, an S3 bucket policy should deny all HTTP requests to its objects and allow only HTTPS requests. HTTPS uses Transport Layer Security (TLS) to encrypt data, which preserves integrity and prevents tampering.

Suggest Edits

Risk Level: High
Cloud Entity: Simple Storage Service (S3)
CloudGuard Rule ID: D9.AWS.CRY.04
Covered by Spectral: Yes
Category: Storage

GSL LOGIC

S3Bucket should have policy.Statement contain [Effect='Deny' and Condition.Bool.aws:SecureTransport='false' and ((Action contain ['s3:GetObject'] and Action contain ['s3:PutObject']) or Action contain ['s3:*'] or Action contain ['*'] ) ]

REMEDIATION

From Portal

Sign in to the AWS Management Console and open the Amazon S3 console at https://console.aws.amazon.com/s3/.
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.
Choose Permissions.
Under Bucket policy, choose Edit. This opens the Edit bucket policy page.
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 add a policy statement that will Deny request with SecureTransport=false
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.
Choose Save changes, which returns you to the Bucket Permissions page.

From TF
If a bucket policy is defined in an aws_s3_bucket policy field, ensure the JSON document contains ALL of the following properties.
One or more valid actions: , s3:, s3:GetObject
Valid effect: Deny
Valid condition: aws:SecureTransport: false
If a bucket policy as defined as an aws_s3_bucket_policy, ensure the JSON document in the policy field contains ALL of the properties listed above.

resource "aws_s3_bucket" "example" {
	bucket = "my-tf-test-bucket"
	# other required fields here
}

resource "aws_s3_bucket_policy" "example2" {
	bucket = aws_s3_bucket.b.id
	
	policy = json_encode({
		Version = "2012-10-17"
		Id      = "MYBUCKET_POLICY"
		Statement = [
		{
			Sid       = "IPAllow"
			Effect    = "Deny"
			Principal = "*"
			Action    = "s3:*"
			Resource = [
			aws_s3_bucket.b.arn,
		"${aws_s3_bucket.b.arn}/*",
			]
			Condition = {
				Bool = {
					"aws:SecureTransport" = "false"
				}
			}
		},
		]
	})

From Command Line
To add a policy to deny non-secure transport, run:

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

References

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 ï¿½ï¿½ï¿½ 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 CIS Foundations v. 1.3.0
AWS CIS Foundations v. 1.4.0
AWS CIS Foundations v. 1.5.0
AWS CIS Foundations v. 2.0.0
AWS CSA CCM v.3.0.1
AWS CloudGuard Best Practices
AWS CloudGuard S3 Bucket Security
AWS CloudGuard SOC2 based on AICPA TSC 2017
AWS CloudGuard Well Architected Framework
AWS GDPR Readiness
AWS HIPAA
AWS HITRUST
AWS HITRUST v11.0.0
AWS ISO 27001:2013
AWS ISO27001:2022
AWS ITSG-33
AWS LGPD regulation
AWS MAS TRM Framework
AWS MITRE ATT&CK Framework v10
AWS MITRE ATT&CK Framework v11.3
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 PCI-DSS 4.0
AWS Security Risk Management
CloudGuard AWS All Rules Ruleset

Updated over 1 year ago