Detect Additional Container Cluster Roles in Sumo Logic CSE
An adversary may add additional roles or permissions to an adversary-controlled user or service account to maintain persistent access to a container orchestration system. For example, an adversary with sufficient permissions may create a RoleBinding or ClusterRoleBinding to bind a Role or ClusterRole to a Kubernetes account. Where ABAC is in use, an adversary may modify a Kubernetes ABAC policy to give the target account additional permissions. This technique may also be used in conjunction with cloud-based RBAC assignments in managed Kubernetes services such as GKE, EKS, and AKS.
MITRE ATT&CK
- Tactic
- Persistence Privilege Escalation
- Technique
- T1098 Account Manipulation
- Sub-technique
- T1098.006 Additional Container Cluster Roles
- Canonical reference
- https://attack.mitre.org/techniques/T1098/006/
Sumo Detection Query
_sourceCategory=kubernetes/audit OR _sourceCategory=*kube*audit*
| json field=_raw "verb" as verb nodrop
| json field=_raw "objectRef.resource" as resource nodrop
| json field=_raw "objectRef.name" as resourceName nodrop
| json field=_raw "objectRef.namespace" as namespace nodrop
| json field=_raw "user.username" as username nodrop
| json field=_raw "sourceIPs[0]" as sourceIP nodrop
| json field=_raw "userAgent" as userAgent nodrop
| json field=_raw "responseStatus.code" as responseCode nodrop
| json field=_raw "requestObject" as requestObject nodrop
| where verb in ("create", "update", "patch")
| where resource in ("clusterrolebindings", "rolebindings", "clusterroles", "roles")
| where responseCode >= 200 and responseCode < 300
| where !(username matches "system:*" and !(username matches "system:serviceaccount:*"))
| if(requestObject matches "*cluster-admin*" or requestObject matches "*system:masters*" or requestObject matches "*system:node-admin*" or requestObject matches "*admin*", 1, 0) as isSensitiveRole
| if(username matches "system:serviceaccount:*", 1, 0) as isServiceAccount
| if(resource = "clusterrolebindings" or resource = "clusterroles", 1, 0) as isClusterScoped
| (isSensitiveRole * 3 + isClusterScoped * 2 + isServiceAccount) as riskScore
| fields _messageTime, verb, resource, resourceName, namespace, username, sourceIP, userAgent, isSensitiveRole, isServiceAccount, isClusterScoped, riskScore, requestObject
| sort by riskScore desc, _messageTime descDetects Kubernetes RBAC role binding creation and modification from kube-apiserver audit logs ingested into Sumo Logic. Parses JSON-structured audit log entries to extract verb, resource type, user identity, response code, and request payload. Applies a weighted risk scoring model (cluster-scoped +2, sensitive role reference +3, service account actor +1) to prioritise high-severity findings. Intended as both a saved search and a signal source for Sumo Logic Cloud SIEM Enterprise (CSE) rule development.
Data Sources
Required Tables
False Positives & Tuning
- Cluster provisioning automation (Terraform, Pulumi, eksctl) that creates default RBAC bindings for managed node groups and system components during cluster creation
- Service mesh installations (Istio, Linkerd, Cilium) that create numerous ClusterRoles and bindings for their control plane components during initial deployment
- Development and staging environments where developers have broad permissions and frequently iterate on RBAC configurations as part of application development workflows
Other platforms for T1098.006
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Create Privileged ClusterRoleBinding for Service Account
Expected signal: Kubernetes API server audit log: verb=create, objectRef.resource=clusterrolebindings, objectRef.name=attacker-cluster-admin-binding, responseStatus.code=201. Second audit event for serviceaccounts create. The requestObject will contain roleRef.name=cluster-admin and subjects referencing the service account.
- Test 2Create Namespace-Scoped RoleBinding for External User
Expected signal: Kubernetes API server audit log: verb=create, objectRef.resource=rolebindings, objectRef.namespace=attacker-test-ns, objectRef.name=attacker-ns-admin-binding, responseStatus.code=201. The requestObject includes roleRef.name=admin and subjects with kind=User and [email protected].
- Test 3Modify Existing ClusterRole to Add Wildcard Permissions
Expected signal: Kubernetes API server audit log: verb=patch, objectRef.resource=clusterroles, objectRef.name=attacker-test-role, responseStatus.code=200. The requestObject contains JSON patch operations adding wildcard rules. This differs from 'create' operations and may be missed by detections that only look for verb=create.
- Test 4Create ABAC Policy Entry via ConfigMap Modification
Expected signal: Kubernetes API server audit log: verb=create, objectRef.resource=configmaps, objectRef.name=attacker-abac-policy. If this were a real kube-system ABAC policy modification: verb=update/patch, objectRef.resource=configmaps, objectRef.namespace=kube-system. The ConfigMap data contains ABAC policy JSON granting wildcard permissions.
References (12)
- https://attack.mitre.org/techniques/T1098/006/
- https://kubernetes.io/docs/reference/access-authn-authz/rbac/
- https://kubernetes.io/docs/reference/access-authn-authz/abac/
- https://kubernetes.io/docs/concepts/security/rbac-good-practices/
- https://blog.aquasec.com/leveraging-kubernetes-rbac-to-backdoor-clusters
- https://cloud.google.com/kubernetes-engine/docs/how-to/iam
- https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts.html
- https://learn.microsoft.com/en-us/azure/aks/concepts-identity
- https://learn.microsoft.com/en-us/azure/aks/monitor-aks
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1098.006/T1098.006.md
- https://www.cncf.io/blog/2021/07/06/practical-approach-to-kubernetes-audit-logging/
- https://cheatsheetseries.owasp.org/cheatsheets/Kubernetes_Security_Cheat_Sheet.html
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