cyberstrikeus 3.1.2 Service account token authentication should not be used for users (Manual)
Profile Applicability
- Level 1 - Master Node
Description
Kubernetes provides service account tokens which are intended for use by workloads running in the Kubernetes cluster, for authentication to the API server.
These tokens are not designed for use by end-users and do not provide for features such as revocation or expiry, making them insecure. A newer version of the feature (Bound service account token volumes) does introduce expiry but still does not allow for specific revocation.
Rationale
With any authentication mechanism the ability to revoke credentials if they are compromised or no longer required, is a key control. Service account token authentication does not allow for this due to the use of JWT tokens as an underlying technology.
Impact
External mechanisms for authentication generally require additional software to be deployed.
Audit
Review user access to the cluster and ensure that users are not making use of service account token authentication.
Remediation
Alternative mechanisms provided by Kubernetes such as the use of OIDC should be implemented in place of service account tokens.
Default Value
Service account token authentication is enabled by default.
CIS Controls
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|---|---|---|---|
| v8 | 6.2 Establish an Access Revoking Process | X | X | X |
| v7 | 16.7 Establish Process for Revoking Access | X | X |