Cis Ocp V190 1.2.23

---
name: cis-ocp-v190-1.2.23
description: "Ensure that the --service-account-lookup argument is set to true (Manual)"
category: cis-openshift
version: "1.9.0"
author: cyberstrike-official
tags: [cis, openshift, kubernetes, redhat, control-plane, api-server, service-account, authentication]
cis_id: "1.2.23"
cis_benchmark: "CIS Red Hat OpenShift Container Platform Benchmark v1.9.0"
tech_stack: [kubernetes, openshift, redhat]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# CIS Red Hat OpenShift Container Platform Benchmark v1.9.0 - Control 1.2.23

## Profile Applicability

- **Level:** 1

## Description

Validate service account before validating token.

## Rationale

If `--service-account-lookup` is not enabled, the `apiserver` only verifies that the authentication token is valid, and does not validate that the service account token mentioned in the request is actually present in `etcd`. This allows using a service account token even after the corresponding service account is deleted. This is an example of time of check to time of use security issue.

## Impact

None.

## Audit Procedure

OpenShift denies access for any OAuth Access token that does not exist in its `etcd` data store. OpenShift does not use the `service-account-lookup` flag even when it is set.

Run the following command:

```bash
oc get configmap config -n openshift-kube-apiserver -ojson | jq -r '.data["config.yaml"]' | jq '.apiServerArguments."service-account-lookup"[]'
```

Verify that if the `--service-account-lookup` argument exists it is set to `true`.

## Remediation

None.

## Default Value

Service account lookup is enabled by default.

## References

1. https://docs.openshift.com/container-platform/latest/operators/operator-reference.html#kube-apiserver-operator_red-hat-operators
2. https://docs.openshift.com/container-platform/latest/operators/operator-reference.html#openshift-apiserver-operator_red-hat-operators
3. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/
4. https://github.com/kubernetes/kubernetes/issues/24167
5. https://en.wikipedia.org/wiki/Time-of-check_to_time-of-use

## CIS Controls

| Controls Version | Control                                                     | IG 1 | IG 2 | IG 3 |
| ---------------- | ----------------------------------------------------------- | ---- | ---- | ---- |
| v8               | 3.3 Configure Data Access Control Lists                     | \*   | \*   | \*   |
| v7               | 14.7 Enforce Access Control to Data through Automated Tools |      |      | \*   |

## MITRE ATT&CK Mappings

| Techniques / Sub-techniques | Tactics | Mitigations |
| --------------------------- | ------- | ----------- |
| T1078                       | TA0001  | M1026       |

## Profile

**Level 1** (Manual)