id: unrestricted-admin-ports
info:
  name: Unrestricted Admin Port Access
  author: princechaddha
  severity: high
  description: |
    Checks for unrestricted ingress on TCP ports 22 (SSH) and 3389 (RDP) in Amazon VPC NACLs, exposing remote server administration to potentially malicious traffic.
  impact: |
    Allows unrestricted remote access, increasing the risk of unauthorized access and potential compromise.
  remediation: |
    Restrict access to ports 22 and 3389 to trusted IPs or IP ranges to adhere to the Principle of Least Privilege (POLP).
  reference:
    - https://docs.aws.amazon.com/vpc/latest/userguide/vpc-network-acls.html
  metadata:
    max-request: 2
  tags: cloud,devops,aws,amazon,vpc,aws-cloud-config
variables:
  region: "us-east-1"

flow: |
  code(1)
  for(let NACLIDs of iterate(template.nacls)){
    set("naclid", NACLIDs)
    code(2)
  }

self-contained: true
code:
  - engine:
      - sh
      - bash
    source: |
      aws ec2 describe-network-acls --region $region --query 'NetworkAcls[*].NetworkAclId' --output json

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

  - engine:
      - sh
      - bash
    source: |
         aws ec2 describe-network-acls --region $region --network-acl-ids $naclid --query 'NetworkAcls[*].Entries[?(RuleAction==`allow`) && (Egress==`false`)] | []' --output json

    matchers-condition: and
    matchers:
      - type: word
        words:
          - "0.0.0.0/0"
          - "CidrBlock"
        condition: and

      - type: word
        words:
          - "22"
          - "3389"
        condition: or

    extractors:
      - type: dsl
        dsl:
          - '"Access to the VPC subnets associated with your NACL " + naclid + " is not restricted."'
# digest: 4a0a00473045022028901135e75f8db19081e604cf1a970f707aba8ba33166b67eba938ebd823cf3022100d783804e924a32e191e35df29155fb31db60251900a5b60efe4aefceb91db299:922c64590222798bb761d5b6d8e72950