The admission control plugin AlwaysPullImages is not set misconfiguration detected in code

Rule Details

Cortex AppSec Rule ID	APPSEC_K8S_80
Category - Subcategory	Kubernetes - Native Security Controls
Provider	OTHER
Severity	MEDIUM
Framework	Helm, Kubernetes, Kustomize

Impact

Always pull images. Setting admission control policy to AlwaysPullImages forces every new pod to pull the required images every time. In a multi-tenant cluster users can be assured that their private images can only be used by those who have the credentials to pull them. Without this admission control policy, once an image has been pulled to a node, any pod from any user can use it simply by knowing the image's name, without any authorization check against the image ownership. When this plug-in is enabled, images are always pulled prior to starting containers, which means valid credentials are required.

How to Fix

Kind: Pod [source,go]

{ "apiVersion: v1 kind: Pod metadata: creationTimestamp: null labels: component: kube-apiserver tier: control-plane name: kube-apiserver namespace: kube-system spec: containers:

• command:
• • kube-apiserver
• • --enable-admission-plugins=AlwaysPullImages image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0 ...", }

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