Kubernetes Suspicious Self-Subject Review via Unusual User Agent

Last updated 8 days ago on 2026-01-30

Created 4 years ago on 2022-06-30

About

This rule detects when a service account or node attempts to enumerate their own permissions via the selfsubjectaccessreview or selfsubjectrulesreview APIs via an unusual user agent. This is highly unusual behavior for non-human identities like service accounts and nodes. An adversary may have gained access to credentials/tokens and this could be an attempt to determine what privileges they have to facilitate further movement or execution within the cluster.

Tags

Data Source: KubernetesDomain: KubernetesUse Case: Threat DetectionTactic: DiscoveryLanguage: kuery

Severity

low

Risk Score

MITRE ATT&CK™

Discovery (TA0007)(external, opens in a new tab or window)

↳ Container and Resource Discovery (T1613)(external, opens in a new tab or window)

False Positive Examples

An administrator may submit this request as an "impersonatedUser" to determine what privileges a particular service account has been granted. However, an adversary may utilize the same technique as a means to determine the privileges of another token other than that of the compromised account.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: New Terms Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-kubernetes.audit_logs-*
Related Integrations: kubernetes(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗event.dataset : "kubernetes.audit_logs" and
kubernetes.audit.annotations.authorization_k8s_io/decision:"allow" and
kubernetes.audit.verb:"create" and
kubernetes.audit.objectRef.resource:("selfsubjectaccessreviews" or "selfsubjectrulesreviews") and (
  kubernetes.audit.user.username:(system\:serviceaccount\:* or system\:node\:*) or
  kubernetes.audit.impersonatedUser.username:(system\:serviceaccount\:* or system\:node\:*)
) and kubernetes.audit.userAgent:(* and not (*kubernetes/$Format))

Install detection rules in Elastic Security

Detect Kubernetes Suspicious Self-Subject Review via Unusual User Agent 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(external, opens in a new tab or window).