Guides

Minimize the admission of root containers (PSP)

Do not generally permit containers to be run as the root user. Containers may run as any Linux user. Containers which run as the root user, whilst constrained by Container Runtime security features still have a escalated likelihood of container breakout. Ideally, all containers should run as a defined non-UID 0 user. There should be at least one CloudGuard Admission Control (CAC) rule or PodSecurityPolicy (PSP) defined which does not permit root users in a container. If you need to run root containers, this should be defined in a separate CAC rule or PSP and you should carefully check RBAC controls to ensure that only limited service accounts and users are given permission to access that CAC rule or PSP.

Suggest Edits

Risk Level: High
Cloud Entity: Pod Security Policies
CloudGuard Rule ID: D9.K8S.IAM.27
Covered by Spectral: Yes
Category: Security, Identity, & Compliance

GSL LOGIC

KubernetesPodSecurityPolicy should have spec.runAsUser.rule like 'MustRunAsNonRoot' or ( spec.runAsUser.rule='MustRunAs' and spec.runAsUser.ranges contain [ min>0 ])

REMEDIATION

Create a CAC rule or PSP as described in the Kubernetes documentation, ensuring that the .spec.runAsUser.rule is set to either MustRunAsNonRoot or MustRunAs with the range of UIDs not including 0.

References

  1. https://kubernetes.io/docs/concepts/policy/pod-security-policy/#enabling-pod-security-policies

Pod Security Policies

A Pod Security Policy is a cluster-level resource that controls security sensitive aspects of the pod specification. The PodSecurityPolicy objects define a set of conditions that a pod must run with in order to be accepted into the system, as well as defaults for the related fields.

Compliance Frameworks

  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.0.1
  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.1.0
  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.2.0
  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.3.0
  • CIS Google Kubernetes Engine (GKE) Benchmark v1.2.0
  • CIS Google Kubernetes Engine (GKE) Benchmark v1.4.0
  • CIS Kubernetes Benchmark v1.23
  • CIS Kubernetes Benchmark v1.5.1
  • CIS Kubernetes Benchmark v1.6.1
  • CIS Microsoft Kubernetes Engine (AKS) Benchmark v1.1.0
  • CIS Microsoft Kubernetes Engine (AKS) Benchmark v1.3.0
  • Kubernetes NIST.SP.800-190
  • Kubernetes v.1.13 CloudGuard Best Practices
  • Kubernetes v.1.14 CloudGuard Best Practices

Updated over 1 year ago