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.

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.

Solution

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

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.

See Also

https://workbench.cisecurity.org/benchmarks/17568

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