AWS EKS Authentication Configuration Modified

Last updated 14 days ago on 2026-10-09

Created 3 months ago on 2026-08-03

About

Detects modifications to the aws-auth ConfigMap in Amazon EKS clusters. The aws-auth ConfigMap maps AWS IAM roles and users to Kubernetes RBAC groups, an attacker who modifies it can grant any IAM role cluster-admin access by adding a mapping to the system:masters group. This is a well-documented persistence technique that survives pod restarts, node replacements, and RBAC changes because the authentication mapping exists outside of normal Kubernetes Role objects. Modifications to aws-auth are rare in normal operations, the ConfigMap is typically set during cluster provisioning and updated only during node group or access configuration changes.

Tags

Domain: CloudDomain: ContainersPlatform: AWSPlatform: KubernetesData Source: AWSData Source: Amazon Web ServicesData Source: Kubernetes API Server Audit LogsService: AWS EKSUse Case: Threat DetectionTactic: PersistenceTactic: Privilege EscalationRule Type: Custom Query (KQL)Profile: BetaLanguage: kuery

Severity

high

Risk Score

MITRE ATT&CK™

Persistence (TA0003)(external, opens in a new tab or window)

↳ Account Manipulation (T1098)(external, opens in a new tab or window)

Privilege Escalation (TA0004)(external, opens in a new tab or window)

↳ Account Manipulation (T1098)(external, opens in a new tab or window)

False Positive Examples

Legitimate node group lifecycle, cluster upgrades, or infrastructure-as-code (Terraform, CloudFormation, eksctl) may update aws-auth during expected change windows. Baseline automation identities and expand exclusions beyond eks:kms-storage-migrator if your environment uses additional known controllers.

License

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

Definition

Rule Type: Query (Kibana Query Language)
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-aws.eks_audit-*
Related Integrations: aws(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗data_stream.dataset:"aws.eks_audit" and
aws.eks.audit.objectRef.resource:"configmaps" and
aws.eks.audit.objectRef.name:"aws-auth" and
aws.eks.audit.verb:("update" or "patch" or "delete") and
aws.eks.audit.objectRef.namespace:"kube-system" and
aws.eks.audit.annotations.authorization_k8s_io/decision:"allow" and
not user.name:"eks:kms-storage-migrator"

Install detection rules in Elastic Security

Detect AWS EKS Authentication Configuration Modified 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).