Title

The Kubernetes Scheduler must have secure binding. (Cat II impact)

Discussion

Limiting the number of attack vectors and implementing authentication and encryption on the endpoints available to external sources is paramount when securing the overall Kubernetes cluster. The Scheduler API service exposes port 10251/TCP by default for health and metrics information use. This port does not encrypt or authenticate connections. If this port is exposed externally, an attacker can use this port to attack the entire Kubernetes cluster. By setting the bind address to localhost (i.e., 127.0.0.1), only those internal services that require health and metrics information can access the Scheduler API.

Check Content

Change to the /etc/kubernetes/manifests directory on the Kubernetes Control Plane. Run the command: grep -i bind-address * If the setting "bind-address" is not set to "127.0.0.1" or is not found in the Kubernetes Scheduler manifest file, this is a finding.

Fix Text

Edit the Kubernetes Scheduler manifest file in the /etc/kubernetes/manifests directory on the Kubernetes Control Plane. Set the argument "--bind-address" to "127.0.0.1".

Additional Identifiers

Rule ID: SV-242384r960792_rule

Vulnerability ID: V-242384

Group Title: SRG-APP-000033-CTR-000090

Expert Comments

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