| name | cis-k8s-v1120-5.1.11 |
| description | Minimize access to the approval sub-resource of certificatesigningrequests objects (Manual) |
| category | cis-k8s |
| version | 1.12.0 |
| author | cyberstrike-official |
| tags | ["cis","kubernetes","policies","rbac","service-accounts"] |
| cis_id | 5.1.11 |
| cis_benchmark | CIS Kubernetes Benchmark v1.12.0 |
| tech_stack | ["kubernetes"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
5.1.11 Minimize access to the approval sub-resource of certificatesigningrequests objects (Manual)
Profile Applicability
Description
Users with access to the update the approval sub-resource of CertificateSigningRequests objects can approve new client certificates for the Kubernetes API effectively allowing them to create new high-privileged user accounts.
This can allow for privilege escalation to full cluster administrator, depending on users configured in the cluster.
Rationale
The ability to update certificate signing requests should be limited.
Audit Procedure
Review the users who have access to update the approval sub-resource of CertificateSigningRequests objects in the Kubernetes API.
Remediation
Where possible, remove access to the approval sub-resource of CertificateSigningRequests objects.
References
- https://kubernetes.io/docs/concepts/security/rbac-good-practices/#csrs-and-certificate-issuing
CIS Controls
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|
| v8 | 6.8 Define and Maintain Role-Based Access Control | | | X |
| v7 | 14 Controlled Access Based on the Need to Know | | | |
