Disallow Privilege Escalation

Description

Privilege escalation (such as via set-user-ID or set-group-ID file mode) should not be allowed. This is Linux only policy in v1.25+ (spec.os.name != windows)

Restricted Fields

• spec.containers[*].securityContext.allowPrivilegeEscalation
• spec.initContainers[*].securityContext.allowPrivilegeEscalation
• spec.ephemeralContainers[*].securityContext.allowPrivilegeEscalation

Allowed Values

• false

Kyverno Policy

Refer to the Nirmata curated policies - disallow-privilege-escalation.yaml

References

Configuration Settings

The below configuration indicates that if the deployed resource contains one of ephemeralContainers or initContainers or containers in their spec field, AND if securityContext.allowPrivilegeEscalation field is present, then the only acceptable value is false to be conformant with this security control. If the securityContext.allowPrivilegeEscalation field is not present, then the resource is conformant by default.

=(ephemeralContainers):
- securityContext:
    allowPrivilegeEscalation: "false"
=(initContainers):
- securityContext:
    allowPrivilegeEscalation: "false"
containers:
- securityContext:
    allowPrivilegeEscalation: "false"

Resource Example

Below is a Deployment resource example where securityContext.allowPrivilegeEscalation is set to false for all initContainers and containers.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: gooddeployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app
  template:
    metadata:
      labels:
        app: app
    spec:
      initContainers:
      - name: initcontainer01
        image: dummyimagename
        securityContext:
          allowPrivilegeEscalation: false
      - name: initcontainer02
        image: dummyimagename
        securityContext:
          allowPrivilegeEscalation: false
      containers:
      - name: container01
        image: dummyimagename
        securityContext:
          allowPrivilegeEscalation: false
      - name: container02
        image: dummyimagename
        securityContext:
          allowPrivilegeEscalation: false