minimize-added-capabilities: Minimize container added capabilities

id: minimize-added-capabilities

info:
  name: Minimize container added capabilities
  author: princechaddha
  severity: high
  description: Checks for containers in Kubernetes Deployments with added capabilities beyond the default set, increasing security risks.
  impact: |
    Containers with additional capabilities are granted more privileges than necessary, potentially allowing them to bypass intended security restrictions. This increases the risk of exploitation and unauthorized access.
  remediation: |
    Ensure that no unnecessary capabilities are added to containers within Kubernetes Deployments. Use security contexts to define the minimum necessary privileges.
  reference:
    - https://kubernetes.io/docs/tasks/configure-pod-container/security-context/
  tags: cloud,devops,kubernetes,k8s,devsecops,deployments,k8s-cluster-security

flow: |
  code(1);
  for (let deployment of template.items) {
    set("deployment", deployment)
    javascript(1);
  }

self-contained: true
code:
  - engine:
      - sh
      - bash
    source: kubectl get deployments --all-namespaces --output=json
    extractors:
      - type: json
        name: items
        internal: true
        json:
          - '.items[]'

javascript:
  - code: |
        deployment = JSON.parse(template.deployment);
        for (const container of deployment.spec.template.spec.containers) {
          if (container.securityContext && container.securityContext.capabilities && container.securityContext.capabilities.add && container.securityContext.capabilities.add.length > 0) {
            let addedCaps = container.securityContext.capabilities.add.join(', ');
            let result = (`Deployment '${deployment.metadata.name}' in namespace '${deployment.metadata.namespace}' has added capabilities: ${addedCaps}.`);
            Export(result);
          }
        }

    extractors:
      - type: dsl
        dsl:
          - response
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