azure-aks-api-unrestricted: Azure AKS API Server Access Unrestricted

id: azure-aks-api-unrestricted
info:
  name: Azure AKS API Server Access Unrestricted
  author: princechaddha
  severity: high
  description: |
    Ensure that Azure Kubernetes Service (AKS) clusters are configured to use the API Server Authorized IP Address Ranges feature in order to limit which IP addresses and CIDRs can access the Kubernetes control plane.
  impact: |
    Without API Server Authorized IP Address Ranges configured, unauthorized IP addresses may access the Kubernetes API Server, leading to potential security vulnerabilities.
  remediation: |
    Configure the AKS clusters to use API Server Authorized IP Address Ranges by setting the appropriate IP ranges in the AKS configuration to ensure that only authorized IPs have access to the Kubernetes control plane.
  reference:
    - https://docs.microsoft.com/en-us/azure/aks/api-server-authorized-ip-ranges
  tags: cloud,devops,azure,microsoft,aks,azure-cloud-config

flow: |
  code(1);
  for (let ClusterData of iterate(template.clusterList)) {
    ClusterData = JSON.parse(ClusterData);
    set("name", ClusterData.name);
    set("resourceGroup", ClusterData.resourceGroup);
    code(2);
  }

self-contained: true
code:
  - engine:
      - sh
      - bash
    source: |
      az aks list --output json --query '[*].{name:name, resourceGroup:resourceGroup}'

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

  - engine:
      - sh
      - bash
    source: |
      az aks show --name "$name" --resource-group "$resourceGroup" --query 'apiServerAccessProfile.authorizedIpRanges'

    matchers-condition: and
    matchers:
      - type: word
        part: body
        negative: true

    extractors:
      - type: dsl
        dsl:
          - 'name + " in " + resourceGroup + " does not have authorized IP ranges configured for AKS API server access"'
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