id: sns-topic-public-accessible

info:
  name: Public Access of SNS Topics via Policy
  author: Ritesh_Gohil(#L4stPL4Y3R)
  severity: high
  description: |
    This template checks if Amazon SNS topics are configured to prevent public access via topic policies.
  reference:
    - https://docs.aws.amazon.com/sns/latest/api/API_GetTopicAttributes.html
  tags: cloud,devops,aws,amazon,sns,aws-cloud-config

flow: |
  code(1)
  for (let topicArn of iterate(template.topics)) {
    set("topicArn", topicArn)
    code(2)
  }

self-contained: true
code:
  - engine:
      - sh
      - bash
    source: |
      aws sns list-topics --query 'Topics[*].TopicArn'

    extractors:
      - type: json
        internal: true
        name: topics
        json:
          - '.[]'

  - engine:
      - sh
      - bash
    source: |
      aws sns get-topic-attributes --topic-arn $topicArn --query Attributes.Policy --output text

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - '"Effect":"Allow"'

      - type: word
        part: body
        words:
          - '"Principal":{"AWS":"*"}'

      - type: regex
        part: body
        negative: true
        regex:
          - '"Condition"'

    extractors:
      - type: dsl
        dsl:
          - '"The SNS topic " + topicArn + " is publicly accessible via Policy"'
# digest: 4a0a0047304502200dff8839ea05345d4fbf9399ef0c6b3b5efd891edbfcc049b16f9509cc6147ef022100f333312e0dfe72993ca40c3ad6b5ba91e7237fa0871eb620f2ede5529c5ab328:366f2a24c8eb519f6968bd8801c08ebe