CVE-2025-64171 is a vulnerability classified under CWE-862 (Missing Authorization) found in the marin3r project, a lightweight, Custom Resource Definition (CRD) based Envoy control plane designed for Kubernetes environments. The flaw exists in versions 0.13.3 and earlier within the DiscoveryServiceCertificate component, which manages certificate discovery and secret access across Kubernetes namespaces. Due to insufficient authorization checks, users can bypass Kubernetes Role-Based Access Control (RBAC) restrictions and access secrets stored in namespaces to which they should not have access. This cross-namespace secret access vulnerability compromises the confidentiality of sensitive data such as credentials, tokens, or keys stored as Kubernetes secrets. The vulnerability requires no authentication or user interaction and can be exploited remotely over the network, making it highly accessible to attackers with access to the cluster. The CVSS 4.0 vector (AV:N/AC:L/AT:N/UI:N/VC:H/VI:N/VA:N) reflects a network attack vector with low complexity, no privileges or user interaction needed, and a high impact on confidentiality. The issue was addressed in marin3r version 0.13.4 by implementing proper authorization checks to enforce namespace boundaries and prevent unauthorized secret access. Although no known exploits are reported in the wild, the severity and ease of exploitation make this a critical vulnerability for Kubernetes clusters using marin3r. Organizations relying on this control plane should prioritize upgrading to the fixed version and auditing their secret management and RBAC policies to ensure no unauthorized access is possible.

The primary impact of CVE-2025-64171 is the unauthorized disclosure of sensitive secrets across Kubernetes namespaces, which can lead to credential theft, privilege escalation, lateral movement, and potential full cluster compromise. For European organizations, especially those operating multi-tenant or segmented Kubernetes environments, this vulnerability threatens the confidentiality of secrets that protect critical infrastructure, applications, and data. Exposure of secrets such as API keys, database credentials, or TLS certificates can facilitate further attacks on internal systems or cloud services. Given the widespread adoption of Kubernetes and cloud-native technologies in Europe, particularly in sectors like finance, healthcare, and government, the risk of data breaches and regulatory non-compliance (e.g., GDPR) is significant. Additionally, the lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the likelihood of exploitation if clusters are accessible. The vulnerability could also undermine trust in managed Kubernetes services and impact operational continuity if secrets are compromised and services disrupted.

To mitigate CVE-2025-64171, European organizations should immediately upgrade marin3r to version 0.13.4 or later, where the authorization checks have been properly implemented. Beyond patching, organizations should enforce strict Kubernetes RBAC policies and namespace isolation to minimize secret exposure risks. Implement network segmentation and restrict access to the Kubernetes API server to trusted users and systems only. Regularly audit and rotate Kubernetes secrets to limit the impact of any potential exposure. Employ Kubernetes security tools that monitor for anomalous secret access or privilege escalations. Consider using external secret management solutions that provide additional access controls and auditing capabilities. Finally, conduct security reviews and penetration testing focused on Kubernetes control plane components to identify and remediate similar authorization weaknesses proactively.