Description

Recent analysis has discovered serious vulnerabilities in Amazon Elastic Kubernetes Service (EKS), potentially exposing AWS credentials and enabling attackers to escalate privileges across cloud infrastructures. These vulnerabilities primarily arise from misconfigured containers and excessive privileges, presenting ongoing challenges in securing large-scale Kubernetes deployments. Amazon EKS is a managed platform that streamlines Kubernetes deployment on AWS by automating control plane management and seamlessly integrating with AWS services for networking, security, and storage. A key feature, EKS Pod Identity, enables pods to access AWS resources using temporary credentials provided by the eks-pod-identity-agent running on each node. Security concerns surface when containers are granted elevated permissions such as hostNetwork: true, which permits monitoring of node network traffic. This can lead to the interception of sensitive credentials transmitted over plaintext HTTP between the pod and the identity agent. Since these credentials are not bound to a specific node, intercepted data can be reused by attackers in other parts of the environment. Demonstrations using standard tools like tcpdump have shown how easily these credentials can be captured and exploited, amplifying the potential for unauthorized access and privilege escalation. An additional attack vector involves API spoofing. Containers with CAP_NET_ADMIN privileges, even without CAP_NET_RAW, can alter network interfaces to shut down the legitimate identity agent and deploy a rogue HTTP server in its place. This rogue server can intercept token requests and harvest valid AWS credentials, revealing another layer of risk due to permissive container configurations and insufficient network security controls. The vulnerabilities were reported to Amazon via the Trend Micro Zero Day Initiative as ZDI-CAN-26891. AWS clarified that the observed behavior falls within the expected trust boundaries of the node, consistent with the shared responsibility model. To reduce exposure, security experts recommend enforcing least-privilege principles, limiting host-level permissions, and routinely auditing container configurations to strengthen cloud infrastructure security.