cyberstrikeus 5.1.11 Minimize access to the approval sub-resource of certificatesigningrequests objects (Manual)
Profile Applicability
- Level 1 - Master Node
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
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.