Critical RCE Vulnerability Discovered in Ingress-NGINX Admission Controller v1.11.1

Critical Remote Code Execution Flaw in Ingress-NGINX Admission Controller

Security researchers have identified a severe vulnerability in Ingress-NGINX Admission Controller version 1.11.1 that allows remote code execution (RCE) via file descriptor (FD) injection. The exploit, cataloged under Exploit-DB ID 52475, highlights a critical risk for Kubernetes environments leveraging this component.

Technical Details of the Vulnerability

The flaw stems from improper handling of file descriptors in the admission controller, enabling attackers to inject malicious file descriptors into the process. This manipulation can lead to arbitrary code execution with the privileges of the affected service. The vulnerability is particularly concerning due to:

• Remote exploitability: Attackers can trigger the flaw without local access.
• Privilege escalation potential: Successful exploitation may grant control over the Kubernetes cluster.
• Low attack complexity: The exploit does not require advanced techniques, increasing the likelihood of widespread attacks.

At present, no CVE ID has been assigned to this vulnerability, though security teams are urged to monitor updates from the Ingress-NGINX project for official advisories.

Impact Analysis

The RCE vulnerability poses a high-severity risk to organizations using Ingress-NGINX Admission Controller v1.11.1. Potential consequences include:

• Unauthorized cluster access: Attackers could gain control over Kubernetes workloads, leading to data breaches or service disruption.
• Lateral movement: Compromised controllers may serve as entry points for further attacks within the network.
• Compliance violations: Unpatched systems could fail regulatory requirements for secure container orchestration.

Recommendations for Security Teams

1. Immediate Patch Deployment: Upgrade to the latest stable version of Ingress-NGINX Admission Controller as soon as a fix is released.
2. Network Segmentation: Isolate admission controllers from untrusted networks to limit exposure.
3. Monitoring and Detection: Deploy intrusion detection systems (IDS) to identify suspicious file descriptor activity or unauthorized process execution.
4. Access Controls: Restrict permissions for the admission controller to minimize potential damage from exploitation.
5. Incident Response Planning: Prepare containment and recovery procedures for potential RCE incidents.

Security teams should prioritize this vulnerability due to its remote exploitability and high impact on Kubernetes security. Follow Exploit-DB for technical proof-of-concept details and updates from the Ingress-NGINX maintainers.