Adds a Capability Other Than NET_BIND_SERVICE

apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicy
metadata:
  name: ephemeralcontainer-capabilities-add-netbindservice
  annotations:
    kubeapt.io/uuid: "d8cfe5f0-c5f9-4bb8-87e0-327213d313ec"
    security.kubeapt.io/displayName: "Adds a Capability Other Than NET_BIND_SERVICE"
    security.kubeapt.io/description: "Added capabilities other than NET_BIND_SERVICE give an ephemeral debug container kernel privileges such as raw socket access, process tracing and filesystem mounting, extending its reach past its namespace onto the node."
    security.kubeapt.io/resource: "EphemeralContainers"
    security.kubeapt.io/severity: "Moderate"
    security.kubeapt.io/remediation: "Remove every entry from the added capability list except NET_BIND_SERVICE, or drop the list entirely. Field: spec.ephemeralContainers[*].securityContext.capabilities.add."
    security.kubeapt.io/product: "Kubernetes"
spec:
  failurePolicy: Fail
  matchConstraints:
    resourceRules:
    - apiGroups:
      - ''
      apiVersions:
      - v1
      operations:
      - CREATE
      - UPDATE
      resources:
      - pods
    - apiGroups:
      - ''
      apiVersions:
      - v1
      operations:
      - CREATE
      - UPDATE
      resources:
      - pods/ephemeralcontainers
  variables:
  - name: allowedCaps
    expression: |
      ["NET_BIND_SERVICE"]
  validations:
  - expression: |
      (has(object.spec.os) &&
       has(object.spec.os.name) &&
       object.spec.os.name.lowerAscii() == "windows") ||
      !has(object.spec.ephemeralContainers) || object.spec.ephemeralContainers.all(ec,
        !has(ec.securityContext) ||
        !has(ec.securityContext.capabilities) ||
        !has(ec.securityContext.capabilities.add) ||
        ec.securityContext.capabilities.add.all(cap,
          variables.allowedCaps.exists(a, a == cap)
        )
      )
    message: |
      spec.ephemeralContainers[*].securityContext.capabilities.add must be undefined/nil or contain only "NET_BIND_SERVICE".