Detections
Analytics
3.2.6 Ensure that the --make-iptables-util-chains argument is set to true
Information
Allow Kubelet to manage iptables.Kubelets can automatically manage the required changes to iptables based on how you choose your networking options for the pods. It is recommended to let kubelets manage the changes to iptables. This ensures that the iptables configuration remains in sync with pods networking configuration. Manually configuring iptables with dynamic pod network configuration changes might hamper the communication between pods/containers and to the outside world. You might have iptables rules too restrictive or too open.
Solution
Remediation Method 1:If modifying the Kubelet config file, edit the kubelet-config.json file /etc/kubernetes/kubelet/kubelet-config.json and set the below parameter to true
"makeIPTablesUtilChains": true
Ensure that /etc/systemd/system/kubelet.service.d/10-kubelet-args.conf does not set the --make-iptables-util-chains argument because that would override your Kubelet config file.
Remediation Method 2:
If using executable arguments, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubelet-args.conf on each worker node and add the below parameter at the end of the KUBELET_ARGS variable string.
--make-iptables-util-chains:true
Remediation Method 3:
If using the api configz endpoint consider searching for the status of "makeIPTablesUtilChains.: true by extracting the live configuration from the nodes running kubelet.
**See detailed step-by-step configmap procedures in
Reconfigure a Node's Kubelet in a Live Cluster
, and then rerun the curl statement from audit process to check for kubelet configuration changes
kubectl proxy --port=8001 &
export HOSTNAME_PORT=localhost:8001 (example host and port number)
export NODE_NAME=gke-cluster-1-pool1-5e572947-r2hg (example node name from "kubectl get nodes")
curl -sSL "http://${HOSTNAME_PORT}/api/v1/nodes/${NODE_NAME}/proxy/configz"
For all three remediations: Based on your system, restart the kubelet service and check status
systemctl daemon-reload
systemctl restart kubelet.service
systemctl status kubelet -l
Impact:
Kubelet would manage the iptables on the system and keep it in sync. If you are using any other iptables management solution, then there might be some conflicts.
See Also
Item Details
Category: CONFIGURATION MANAGEMENT, SYSTEM AND COMMUNICATIONS PROTECTION
References: 800-53|CM-6, 800-53|CM-7, 800-53|SC-23, CSCv7|11.1
Plugin: Unix
Control ID: bc64486ccae17a041ef86d8757f2de4b067b67055f1a54bad6bb25f55d2e6d06