Kubernetes RBAC Wildcard Elevation on Existing Role
editKubernetes RBAC Wildcard Elevation on Existing Role
editFlags an existing Role or ClusterRole being changed (patch or update) so the effective rules become cluster-admin-like: wildcard on every API resource and wildcard on every verb. That is usually a deliberate privilege expansion, not a typo. RequestResponse audit and the response body are required so the detection reads the merged role after apply; loopback source IPs are ignored.
Rule type: esql
Rule indices: None
Severity: high
Risk score: 73
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Data Source: Kubernetes
- Domain: Kubernetes
- Use Case: Threat Detection
- Tactic: Privilege Escalation
- Resources: Investigation Guide
Version: 2
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
editTriage and analysis
Investigating Kubernetes RBAC Wildcard Elevation on Existing Role
Someone patched or updated a Role or ClusterRole so the stored rules grant star verbs and star resources—near cluster-admin breadth on that scope. Confirm the actor (user, group, impersonation), client, and non-loopback source IP; then see who can bind that role.
Possible investigation steps
- Diff the role YAML before and after; list RoleBindings and ClusterRoleBindings that reference it and which subjects gained the widened access.
- In the same window, check secret reads, exec, and further RBAC changes from the same identity.
False positive analysis
- Approved GitOps or vendor upgrades sometimes widen a known ClusterRole; allowlist stable automation when documented.
Response and remediation
- Revert the role, drop unexpected bindings, rotate credentials for the actor, and block future wildcard RBAC outside governed pipelines (policy-as-code, PR-only RBAC).
Rule query
editfrom logs-kubernetes.audit_logs-* metadata _id, _index, _version
| where
kubernetes.audit.objectRef.resource in ("roles", "clusterroles") and
kubernetes.audit.verb in ("update", "patch") and
`kubernetes.audit.annotations.authorization_k8s_io/decision` == "allow" and
kubernetes.audit.level == "RequestResponse" and
kubernetes.audit.stage == "ResponseComplete" and
kubernetes.audit.sourceIPs is not null and
not kubernetes.audit.sourceIPs in ("::1", "127.0.0.1") and
KQL(""" kubernetes.audit.responseObject.rules.verbs:"*" and kubernetes.audit.responseObject.rules.resources:"*" """)
| keep user.name, user_agent.original, event.action, source.ip, kubernetes.audit.verb, kubernetes.audit.objectRef.resource, kubernetes.audit.objectRef.name, kubernetes.audit.requestURI, kubernetes.audit.user.username, kubernetes.audit.user.groups, `kubernetes.audit.annotations.authorization_k8s_io/decision`, event.original, _id, _version, _index, data_stream.namespace
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
-
Technique:
- Name: Account Manipulation
- ID: T1098
- Reference URL: https://attack.mitre.org/techniques/T1098/
-
Sub-technique:
- Name: Additional Container Cluster Roles
- ID: T1098.006
- Reference URL: https://attack.mitre.org/techniques/T1098/006/