json.aws.security.public-s3-policy-statement.public-s3-policy-statement

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Detected public S3 bucket policy. This policy allows anyone to access certain properties of or items in the bucket. Do not do this unless you will never have sensitive data inside the bucket.

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Defintion

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rules:
  - id: public-s3-policy-statement
    pattern: |
      {
        "Effect": "Allow",
        "Principal": "*",
        "Resource": [
          ..., "=~/arn:aws:s3.*/", ...
        ],
        ...
      }
    message: Detected public S3 bucket policy. This policy allows anyone to access
      certain properties of or items in the bucket. Do not do this unless you
      will never have sensitive data inside the bucket.
    metadata:
      owasp:
        - A01:2021 - Broken Access Control
      cwe:
        - "CWE-264: CWE CATEGORY: Permissions, Privileges, and Access Controls"
      references:
        - https://docs.aws.amazon.com/AmazonS3/latest/dev/WebsiteAccessPermissionsReqd.html
      category: security
      technology:
        - aws
      subcategory:
        - vuln
      likelihood: LOW
      impact: HIGH
      confidence: MEDIUM
      license: Commons Clause License Condition v1.0[LGPL-2.1-only]
      vulnerability_class:
        - Improper Authorization
    severity: WARNING
    languages:
      - json

Examples

public-s3-policy-statement.json

{
    "Version": "2012-10-17",
    "Statement": [
        // ruleid:public-s3-policy-statement
        {
            "Sid": "PublicReadGetObject",
            "Effect": "Allow",
            "Principal": "*",
            "Action": [
                "s3:GetObject"
            ],
            "Resource": [
                "arn:aws:s3:::example.com/*"
            ]
        },
        // ok:public-s3-policy-statement
        {
            "Sid": "CloudFront Origin Access Identity",
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws:iam::cloudfront:user/CloudFront Origin Access Identity ECLOUDFRONTOAI"
            },
            "Action": [
                "s3:GetObject"
            ],
            "Resource": [
                "arn:aws:s3:::example.com/*"
            ]
        }
    ]
}