Ensure that default service accounts are not actively used.

チェック方法

監査方法: シェルコマンド

sa=$(kubectl get serviceaccounts -A -o go-template='{{range .items}}{{if eq .metadata.name "default"}}{{.metadata.namespace}} {{.automountServiceAccountToken}}{{"\n"}}{{end}}{{end}}') || exit 1
rb=$(kubectl get rolebindings,clusterrolebindings -A -o go-template='{{range .items}}{{$b:=.metadata.name}}{{$bn:=.metadata.namespace}}{{range .subjects}}{{if eq .kind "ServiceAccount"}}{{if eq .name "default"}}{{if .namespace}}{{.namespace}}{{else}}{{$bn}}{{end}} {{$b}}{{"\n"}}{{end}}{{end}}{{end}}{{end}}') || exit 1
bad=$(printf '%s\n' "$sa" | awk -v ex='^(kube-system|kube-public|kube-node-lease)$' 'NF && $1 !~ ex && $2!="false" {print "automount: " $1}')
bad2=$(printf '%s\n' "$rb" | awk -v ex='^(kube-system|kube-public|kube-node-lease)$' 'NF && $1 !~ ex {print "binding: " $0}')
if [ -z "$bad$bad2" ]; then echo compliant; else printf '%s\n%s\n' "$bad" "$bad2" | grep . | head -n 25; fi

期待される出力

compliant

修正方法

修正方法: ガイダンスまたは IaC パッチ

Create dedicated service accounts for workloads that need Kubernetes API access or OKE workload identity, and update those workloads to explicitly set serviceAccountName rather than relying on the namespace default service account. For workloads that do not need Kubernetes API access, disable service account token auto mounting and avoid using the default service account as the active workload identity. Also review the default service account in each namespace and ensure it is not bound to unnecessary RBAC permissions. Modify the default service account in each application namespace to set: automountServiceAccountToken: false Then validate workload manifests, because a Pod automountServiceAccountToken setting can override the service account setting, and workloads that actually need Kubernetes API access must use an explicitly assigned service account instead of inheriting default.

このホストをチェック

監査が許可されているマシンで実行してください。スキャンは読み取り専用です。

tmaegis scan --target oke