1.4.2 Ensure that the --bind-address argument is set to 127.0.0.1 (Automated)
Profile Applicability
- Level 1 - Master Node
Description
Do not bind the scheduler service to non-loopback insecure addresses.
Rationale
The Scheduler API service which runs on port 10251/TCP by default is used for health and metrics information and is available without authentication or encryption. As such it should only be bound to a localhost interface, to minimize the cluster's attack surface
Impact
None
Audit
Run the following command on the Control Plane node:
ps -ef | grep kube-scheduler
Verify that the --bind-address argument is set to 127.0.0.1
Remediation
Edit the Scheduler pod specification file /etc/kubernetes/manifests/kube-scheduler.yaml on the Control Plane node and ensure the correct value for the --bind-address parameter
Default Value
By default, the --bind-address parameter is set to 0.0.0.0
References
CIS Controls
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|---|---|---|---|
| v8 | 12.6 Use of Secure Network Management and Communication Protocols | X | X | |
| v7 | 9.2 Ensure Only Approved Ports, Protocols and Services Are Running | X | X |