CNTR-R2-000120 The Kubernetes API server must have the insecure port flag disabled.

Information

By default, the API server will listen on two ports. One port is the secure port and the other port is called the "localhost port". This port is also called the "insecure port", port 8080. Any requests to this port bypass authentication and authorization checks. If this port is left open, anyone who gains access to the host on which the master is running can bypass all authorization and authentication mechanisms put in place, and have full control over the entire cluster.

Close the insecure port by setting the API server's --insecure-port flag to "0", ensuring that the --insecure-bind-address is not set.

Solution

Edit the RKE2 Server configuration file on all RKE2 Server hosts, located at /etc/rancher/rke2/config.yaml, to contain the following:

kube-apiserver-arg:
- insecure-port=0

Once configuration file is updated, restart the RKE2 Server. Run the command:
systemctl restart rke2-server

See Also

https://workbench.cisecurity.org/benchmarks/0

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-3, CAT|I, CCI|CCI-000213, Rule-ID|SV-254558r960792_rule, STIG-ID|CNTR-R2-000120, Vuln-ID|V-254558

Plugin: Unix

Control ID: 7f41c57eddb9e43446a9b77f5e4695e9d56dc13b422be7ecb8b0d767aee30d2c