CVE-2025-4374 is a security vulnerability identified in Red Hat Quay 3, a container image registry platform widely used for managing and distributing container images. The flaw arises when an organization configures Quay to act as a proxy cache. In this setup, if a user or automated robot attempts to pull a container image that has not yet been mirrored or cached locally, the system erroneously grants "Admin" permissions on the newly created repository to that user or robot. This incorrect privilege assignment means that unauthorized users can gain elevated administrative rights over repositories they should not control. The vulnerability does not require any authentication or user interaction to exploit, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact is limited to confidentiality and integrity, with no direct availability impact. The CVSS score of 6.5 (medium severity) reflects the moderate risk posed by this vulnerability. Although no known exploits are reported in the wild, the flaw could allow attackers to manipulate repository contents, potentially injecting malicious images or altering existing ones, thereby compromising the software supply chain. The vulnerability is specific to Red Hat Quay 3, and no affected versions are explicitly listed, but users of this product should consider it relevant. No patches or fixes are currently linked, so mitigation may require configuration changes or monitoring until an official update is released.

For European organizations, especially those relying on containerized applications and DevOps pipelines, this vulnerability poses a significant risk to the integrity and confidentiality of container images. Unauthorized administrative access to repositories could lead to the insertion of malicious code into container images, which can then be deployed across production environments, potentially causing widespread compromise. This risk is heightened in sectors with stringent regulatory requirements such as finance, healthcare, and critical infrastructure, where supply chain security is paramount. The flaw could also undermine trust in software provenance and complicate compliance with European data protection and cybersecurity regulations like GDPR and NIS Directive. Since Red Hat Quay is commonly used in enterprise environments across Europe, organizations using it as a proxy cache should be vigilant. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits once the vulnerability details become widely known.

European organizations should immediately audit their Red Hat Quay 3 deployments to determine if proxy caching is enabled and if the environment is susceptible to this privilege escalation. Until an official patch is released, administrators should consider disabling proxy caching functionality or restricting image pulls to trusted users only. Implement strict access controls and monitoring on repository creation events to detect unauthorized privilege assignments. Employ network segmentation and container image signing to ensure the integrity of images before deployment. Additionally, integrating runtime security tools that can detect anomalous container behavior may help mitigate the impact of compromised images. Organizations should subscribe to Red Hat security advisories for timely patch releases and apply updates promptly once available. Finally, conducting a thorough review of user and robot account permissions in Quay can prevent excessive privileges from being exploited.