CVE-2025-4374 is a vulnerability identified in Red Hat Quay 3, a popular container image registry solution. The flaw arises when an organization acts as a proxy cache for container images. In this scenario, if a user or automated robot pulls an image that has not yet been mirrored in the proxy cache, the system incorrectly assigns 'Admin' privileges on the newly created repository to the entity initiating the pull. This privilege escalation occurs without requiring prior authentication or user interaction, making it easier to exploit remotely. The vulnerability affects the confidentiality and integrity of container repositories by allowing unauthorized users to gain administrative control, potentially enabling them to modify, delete, or expose container images. The CVSS v3.1 base score is 6.5 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, and no user interaction needed. Although no exploits are currently known in the wild, the flaw poses a significant risk in environments where proxy caching is used to optimize container image distribution. The absence of affected version details suggests all Red Hat Quay 3 instances with proxy cache enabled should be considered vulnerable until patched. This vulnerability highlights the importance of strict privilege assignment and validation in container registry operations.

For European organizations, this vulnerability could lead to unauthorized administrative access to container image repositories, risking the integrity and confidentiality of containerized applications. Attackers gaining admin privileges could modify images to include malicious code, disrupt deployment pipelines, or exfiltrate sensitive data embedded in container metadata. Organizations relying on Red Hat Quay 3 for container image management, especially those using proxy caching to optimize network usage, face increased risk of supply chain compromise. Critical sectors such as finance, healthcare, and government, which increasingly use containerized applications, could experience operational disruptions or data breaches. The medium CVSS score indicates a moderate but non-negligible threat, especially given the lack of required authentication and user interaction. The vulnerability could also undermine trust in container image provenance and complicate compliance with European data protection regulations if exploited.

European organizations should immediately audit their Red Hat Quay 3 deployments to identify proxy cache configurations. Until an official patch is released, organizations should consider disabling proxy cache functionality or restricting access to trusted users and robots only. Implement network segmentation and firewall rules to limit external access to the Quay registry. Monitor repository creation events and privilege assignments for anomalies indicating unauthorized admin grants. Employ container image signing and verification to detect unauthorized modifications. Regularly update Red Hat Quay to the latest versions once patches addressing this vulnerability are available. Additionally, integrate container security scanning and runtime protection to detect suspicious behavior stemming from compromised images. Establish strict role-based access controls (RBAC) and enforce the principle of least privilege to minimize the impact of any unauthorized access.