The Kubernetes Scheduler must have secure binding. (Cat II impact)
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.
Change to the /etc/kubernetes/manifests directory on the Kubernetes Master Node. 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.
Edit the Kubernetes Scheduler manifest file in the /etc/kubernetes/manifests directory on the Kubernetes Master Node. Set the argument "--bind-address" to "127.0.0.1".
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