Elastic Security Detection Rules

Kubernetes Anonymous Request Authorized

Last updated 13 days ago on 2025-06-18
Created 3 years ago on 2022-09-13

About

This rule detects when an unauthenticated user request is authorized within the cluster. 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 and /readyz endpoints which are commonly accessed anonymously.
Tags
Data Source: KubernetesTactic: ExecutionTactic: Initial AccessTactic: Defense EvasionLanguage: kuery
Severity
medium
Risk Score
47
MITRE ATT&CK™

Initial Access (TA0001)(opens in a new tab or window)

↳ Valid Accounts (T1078)(opens in a new tab or window)

False Positive Examples
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.
License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Query (Kibana Query Language)
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-kubernetes.audit_logs-*
Related Integrations

kubernetes(opens in a new tab or window)

Query
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 not kubernetes.audit.requestURI:(/healthz* or /livez* or /readyz*)

Install detection rules in Elastic Security

Detect Kubernetes Anonymous Request Authorized in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).