CIS OKE Benchmark v1.8.0 - Control 3.2.2

---
name: cis-oke-v180-3-2-2-6f1687edeea4
description: "Ensure that the --authorization-mode argument is not set to AlwaysAllow (Automated)"
category: cis-oke
version: "1.8.0"
author: cyberstrike-official
tags: [cis, oke, kubernetes, oci, worker-node, kubelet]
cis_id: "3.2.2"
cis_benchmark: "CIS Oracle Cloud Infrastructure Container Engine for Kubernetes (OKE) Benchmark v1.8.0"
tech_stack: [kubernetes, oci, oke]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# CIS OKE Benchmark v1.8.0 - Control 3.2.2

## Profile Applicability

- **Level:** 1

## Description

Do not allow all requests. Enable explicit authorization.

## Rationale

Kubelets, by default, allow all authenticated requests (even anonymous ones) without needing explicit authorization checks from the apiserver. You should restrict this behavior and only allow explicitly authorized requests.

## Impact

Unauthorized requests will be denied.

## Audit Procedure

### Audit Method 1

If using a Kubelet configuration file, check that there is an entry for `--authentication-mode`.

First, SSH to the relevant node.

Run the following command on each node to find the appropriate Kubelet config file:

```bash
find / -name kubelet.service
```

The output of the above command should return the file and location `/etc/systemd/system/kublet.service` which is the location of the Kubelet service config file.

Open the Kubelet service config file:

```bash
sudo more etc/systemd/system/kubelet.service
```

Verify that the `--authentication-mode=Webhook`.

### Audit Method 2

If using the api configz endpoint consider searching for the status of `authentication... "webhook":{"enabled":true}` by extracting the live configuration from the nodes running kubelet.

Set the local proxy port and the following variables and provide proxy port number and node name:

```bash
kubectl proxy --port=8001 &

export HOSTNAME_PORT=localhost:8001 (example host and port number)
export NODE_NAME=10.0.10.4 (example node name from "kubectl get nodes")

curl -sSL "http://${HOSTNAME_PORT}/api/v1/nodes/${NODE_NAME}/proxy/configz"
```

## Remediation

### Remediation Method 1

If modifying the Kubelet service config file, edit the kubelet.service file `/etc/systemd/system/kubelet.service` and set the below parameter:

```
--authorization-mode=Webhook
```

### Remediation Method 2

If using the api configz endpoint consider searching for the status of `"authentication.*webhook":{"enabled":true}` by extracting the live configuration from the nodes running kubelet.

See detailed step-by-step configmap procedures in [Reconfigure a Node's Kubelet in a Live Cluster](https://kubernetes.io/docs/tasks/administer-cluster/reconfigure-kubelet/), and then rerun the curl statement from audit process to check for kubelet configuration changes.

```bash
kubectl proxy --port=8001 &

export HOSTNAME_PORT=localhost:8001 (example host and port number)
export NODE_NAME=10.0.10.4 (example node name from "kubectl get nodes")

curl -sSL "http://${HOSTNAME_PORT}/api/v1/nodes/${NODE_NAME}/proxy/configz"
```

**For all remediations:** Based on your system, restart the `kubelet` service and check status:

```bash
systemctl daemon-reload
systemctl restart kubelet.service
systemctl status kubelet -l
```

## Default Value

See the OKE documentation for the default value.

## References

1. https://kubernetes.io/docs/admin/kubelet/
2. https://kubernetes.io/docs/admin/kubelet-authentication-authorization/#kubelet-authentication
3. https://docs.cloud.oracle.com/en-us/iaas/Content/ContEng/Concepts/contengoverview.htm

## CIS Controls

| Controls Version | Control                                                            | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------------------------------------------------ | ---- | ---- | ---- |
| v8               | 3.3 Configure Data Access Control Lists                            | \*   | \*   | \*   |
| v7               | 9.2 Ensure Only Approved Ports, Protocols and Services Are Running |      | \*   | \*   |

## MITRE ATT&CK Mappings

| Techniques / Sub-techniques | Tactics | Mitigations |
| --------------------------- | ------- | ----------- |
| T1133                       | TA0001  | M1026       |

## Profile

**Level 1** (Automated)