4.3.1 Ensure that the kube-proxy metrics service is bound to localhost

Information

Do not bind the kube-proxy metrics port to non-loopback addresses.

Rationale:

kube-proxy has two APIs which provided access to information about the service and can be bound to network ports. The metrics API service includes endpoints (/metrics and /configz) which disclose information about the configuration and operation of kube-proxy. These endpoints should not be exposed to untrusted networks as they do not support encryption or authentication to restrict access to the data they provide.

Impact:

3rd party services which try to access metrics or configuration information related to kube-proxy will require access to the localhost interface of the node.

Solution

Modify or remove any values which bind the metrics service to a non-localhost address

Default Value:

The default value is 127.0.0.1:10249

See Also

https://workbench.cisecurity.org/benchmarks/16828

Item Details

Category: ACCESS CONTROL, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|AC-18, 800-53|SC-23, CSCv7|9.2

Plugin: Unix

Control ID: 2d9c4dd94fc1d57e43e64c9bd641cbcdfac22210b2ea716933f068d1ba2125e9