Kubernetes attacks
When it applies
A Kubernetes control-plane or node component is reachable (externally or from a pod foothold), or you landed in a container inside a cluster and want to escalate to cluster admin / other tenants.
Why it works
k8s exposes powerful HTTP APIs that are frequently unauthenticated or over-permissioned: anonymous API access, kubelet read/exec on 10250, unauth etcd (all secrets), and mounted service-account tokens with broad RBAC. One over-scoped token = cluster takeover.
Method
- From outside:
kube-hunter; probe API server 6443 (/api/v1anonymous), kubelet 10250 (/pods,/runexec), etcd 2379 (keys→secrets), and exposed dashboards (8443/anonymous). - From a pod: read the mounted token
/var/run/secrets/kubernetes.io/serviceaccount/;kubectl auth can-i --listto see what it grants. - Escalate via RBAC: over-permissioned SA → create/exec pods, read secrets across namespaces,
or
create podswith a hostPath/privileged spec to mount the node (→ node/cluster takeover). - Container→node breakout: privileged pod, hostPID/hostNetwork, or a hostPath mount to the
host filesystem (→
cloud-container-escape). - Loot:
kubectl get secrets -A, cloud IAM via node metadata (→cloud-imds-ssrf).
Gotchas
kubectl auth can-i --listfirst — it tells you exactly what the token can do; don't guess.- Anonymous API/kubelet is common in labs and misconfigured clusters — always test unauth.
- On bug bounty, prove access read-only where possible; creating privileged pods is high-impact — mind RoE.
Verify success
Cluster-level access proven: reading secrets across namespaces, exec into others' pods, or node filesystem/cloud-creds access from an over-scoped token.
References
kube-hunter/peirates; NCC "Kubernetes security"; MITRE ATT&CK Containers.