CVE-2025-1974 is a critical security vulnerability identified in the Kubernetes ingress-nginx controller, affecting all versions up to and including 1.12.0. The root cause is improper isolation or compartmentalization (CWE-653) within the ingress-nginx controller, which allows an unauthenticated attacker who has access to the pod network to execute arbitrary code in the context of the ingress-nginx controller. This is particularly dangerous because the ingress-nginx controller, by default, has access to all Secrets cluster-wide. Exploiting this vulnerability could allow attackers to disclose sensitive information stored in Secrets, such as credentials, tokens, and certificates, and potentially manipulate or disrupt cluster operations. The vulnerability has a CVSS v3.1 score of 9.8, reflecting its critical nature with network attack vector, no required privileges or user interaction, and high impact on confidentiality, integrity, and availability. While no public exploits have been reported yet, the vulnerability’s characteristics make it a prime target for attackers once exploit code becomes available. The ingress-nginx controller is widely used in Kubernetes environments to manage external access to services, making this vulnerability relevant to many organizations using Kubernetes for container orchestration. The issue highlights the risks of excessive privilege and insufficient compartmentalization in cloud-native infrastructure components.

For European organizations, this vulnerability poses a severe risk to the confidentiality, integrity, and availability of Kubernetes clusters. Successful exploitation can lead to full compromise of the ingress-nginx controller, disclosure of all cluster Secrets, and potentially lateral movement within the cluster. This could result in data breaches, service disruptions, and unauthorized access to sensitive systems. Organizations in sectors such as finance, healthcare, government, and critical infrastructure, which heavily rely on Kubernetes for scalable and secure deployments, face heightened risks. The cluster-wide access to Secrets by the ingress-nginx controller means that attackers could retrieve credentials for other services, escalating the attack impact. Given the criticality of cloud-native environments in European digital transformation initiatives, this vulnerability could undermine trust and compliance with regulations like GDPR if exploited. Additionally, the ease of exploitation without authentication or user interaction increases the urgency for mitigation.

1. Immediately restrict network access to the pod network to trusted entities only, using Kubernetes Network Policies or equivalent network segmentation controls to limit who can communicate with ingress-nginx pods. 2. Monitor ingress-nginx controller logs and network traffic for unusual activity indicative of exploitation attempts. 3. Apply ingress-nginx controller updates or patches as soon as they are released by the Kubernetes project to address this vulnerability. 4. Review and minimize the scope of Secrets accessible to the ingress-nginx controller by implementing the principle of least privilege, possibly using Kubernetes RBAC to restrict Secret access. 5. Employ runtime security tools to detect anomalous behavior in ingress-nginx pods, such as unexpected code execution or privilege escalations. 6. Conduct regular security audits of Kubernetes cluster configurations, focusing on ingress controllers and Secret management. 7. Consider deploying ingress-nginx in a more isolated environment or using alternative ingress controllers with stricter compartmentalization until patches are available. 8. Educate DevOps and security teams about this vulnerability to ensure rapid response and remediation.