RBAC Roles with Port-Forwarding Permission

• Query id: 38fa11ef-dbcc-4da8-9680-7e1fd855b6fb
• Query name: RBAC Roles with Port-Forwarding Permission
• Platform: Kubernetes
• Severity: Medium
• Category: Access Control
• URL: Github

Description

Roles or ClusterRoles with RBAC permissions to port-forward into pods can open socket-level communication channels to containers. In case of compromise, attackers may abuse this for direct communication that bypasses network security restrictions
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - yaml file

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: my-namespace
  name: allow-port-forward
rules:
- apiGroups: [""]
  resources: ["pods", "pods/portforward"]
  verbs: ["get", "list", "create"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: allow-port-forward
  namespace: my-namespace
subjects:
- kind: User
  name: bob
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: allow-port-forward
  apiGroup: ""

Code samples without security vulnerabilities

Negative test num. 1 - yaml file

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: my-namespace
  name: allow-port-forward-neg
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "list", "create"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: allow-port-forward-neg
  namespace: my-namespace
subjects:
- kind: User
  name: bob
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: allow-port-forward-neg
  apiGroup: ""