kubectl-kubesec

kubectl-kubesec

This is a kubectl plugin for scanning Kubernetes pods, deployments, daemonsets and statefulsets with kubesec.io

For the admission controller see kubesec-webhook

Install

Install with krew

1. Install krew plugin manager for kubectl.
2. Run kubectl krew install kubesec-scan.
3. Start using by running kubectl kubesec-scan.

Install with curl

For Kubernetes 1.12 or newer:

mkdir -p ~/.kube/plugins/scan && \
curl -sL https://github.com/controlplaneio/kubectl-kubesec/releases/download/1.0.0/kubectl-kubesec_1.0.0_`uname -s`_amd64.tar.gz | tar xzvf - -C ~/.kube/plugins/scan
mv ~/.kube/plugins/scan/scan ~/.kube/plugins/scan/kubectl-scan
export PATH=$PATH:~/.kube/plugins/scan

For Kubernetes older than 1.12:

mkdir -p ~/.kube/plugins/scan && \
curl -sL https://github.com/controlplaneio/kubectl-kubesec/releases/download/0.3.1/kubectl-kubesec_0.3.1_`uname -s`_amd64.tar.gz | tar xzvf - -C ~/.kube/plugins/scan

Usage

Scan a Deployment:

kubectl kubesec-scan -n kube-system deployment kubernetes-dashboard

Result:

kubernetes-dashboard kubesec.io score 7
-----------------
Advise
1. containers[] .securityContext .runAsNonRoot == true
Force the running image to run as a non-root user to ensure least privilege
2. containers[] .securityContext .capabilities .drop
Reducing kernel capabilities available to a container limits its attack surface
3. containers[] .securityContext .readOnlyRootFilesystem == true
An immutable root filesystem can prevent malicious binaries being added to PATH and increase attack cost
4. containers[] .securityContext .runAsUser > 10000
Run as a high-UID user to avoid conflicts with the host's user table
5. containers[] .securityContext .capabilities .drop | index("ALL")
Drop all capabilities and add only those required to reduce syscall attack surface

Scan a DaemonSet:

kubectl kubesec-scan -n weave daemonset weave-scope-agent

Result:

daemonset/weave-scope-agent kubesec.io score -54
-----------------
Critical
1. containers[] .securityContext .privileged == true
Privileged containers can allow almost completely unrestricted host access
2. .spec .hostNetwork
Sharing the host's network namespace permits processes in the pod to communicate with processes bound to the host's loopback adapter
3. .spec .hostPID
Sharing the host's PID namespace allows visibility of processes on the host, potentially leaking information such as environment variables and configuration
4. .spec .volumes[] .hostPath .path == "/var/run/docker.sock"
Mounting the docker.socket leaks information about other containers and can allow container breakout

Scan a StatefulSet:

kubectl kubesec-scan statefulset memcached

Result:

statefulset/memcached kubesec.io score 2
-----------------
Advise
1. .spec .volumeClaimTemplates[] .spec .accessModes | index("ReadWriteOnce")
2. containers[] .securityContext .runAsNonRoot == true
Force the running image to run as a non-root user to ensure least privilege
3. containers[] .securityContext .capabilities .drop
Reducing kernel capabilities available to a container limits its attack surface
4. containers[] .securityContext .readOnlyRootFilesystem == true
An immutable root filesystem can prevent malicious binaries being added to PATH and increase attack cost
5. containers[] .securityContext .runAsUser > 10000
Run as a high-UID user to avoid conflicts with the host's user table

Scan a Pod:

kubectl kubesec-scan -n kube-system pod tiller-deploy-5c688d5f9b-ztjbt

Result:

pod/tiller-deploy-5c688d5f9b-ztjbt kubesec.io score 3
-----------------
Advise
1. containers[] .securityContext .runAsNonRoot == true
Force the running image to run as a non-root user to ensure least privilege
2. containers[] .securityContext .capabilities .drop
Reducing kernel capabilities available to a container limits its attack surface
3. containers[] .securityContext .readOnlyRootFilesystem == true
An immutable root filesystem can prevent malicious binaries being added to PATH and increase attack cost
4. containers[] .securityContext .runAsUser > 10000
Run as a high-UID user to avoid conflicts with the host's user table
5. containers[] .securityContext .capabilities .drop | index("ALL")
Drop all capabilities and add only those required to reduce syscall attack surface