Kubernetes Anonymous Request Authorized by Unusual User Agent
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…
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
Its licence does not clear it for publishing here
Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.
Detection requirements
- Platform
- ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- event_index
Known benign triggers
- 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.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| media.defense.gov/2022/Aug/29/2003066362/-1/-1/0/CTR_KUBERNETES_HARDENING_GUIDANCE_1.2_20220829.PDF | 2 |
From the source
- At source
- Open at source
- Upstream identifier
- 63c057cc-339a-11ed-a261-0242ac120002
- Tagged by the source as
- Data Source: KubernetesDomain: CloudDomain: ContainersDomain: KubernetesNoise: MediumPerformance: FastPlatform: KubernetesResources: Investigation GuideRule Type: New TermsTactic: Defense EvasionTactic: Initial AccessUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3