LoFP LoFP / anonymous access to the api server is a dangerous setting enabled by default. common anonymous connections (e.g., health checks) have been excluded from this rule. all other instances of authorized anonymous requests should be investigated.

Techniques

Sample rules

Kubernetes Anonymous Request Authorized by Unusual User Agent

Description

This rule detects when an unauthenticated user request is authorized within the cluster via an unusual user agent. Attackers may attempt to use anonymous accounts to gain initial access to the cluster or to avoid attribution of their activities within the cluster. This rule excludes the /healthz, /livez, /version and /.well-known/oauth-authorization-server endpoints which are commonly accessed anonymously.

Detection logic

event.dataset:"kubernetes.audit_logs" and
kubernetes.audit.annotations.authorization_k8s_io/decision:"allow" and
kubernetes.audit.user.username:("system:anonymous" or "system:unauthenticated" or not *) and
kubernetes.audit.userAgent:(* and not (*kubernetes/$Format)) and
not kubernetes.audit.requestURI:(/healthz* or /livez* or /readyz* or /version or /.well-known/oauth-authorization-server)