CVE-2025-4374 identifies an incorrect privilege assignment vulnerability in Project Quay, a popular container image registry used for managing and distributing container images. The vulnerability arises specifically when an organization is configured as a proxy cache. In this setup, when a user or automated robot requests to pull a container image that has not yet been mirrored locally, the system erroneously grants the requester Admin permissions on the newly created repository that stores the image. This privilege escalation flaw allows unauthorized users or automated processes to gain administrative control over repositories they should not have access to. Such control can lead to unauthorized image modifications, insertion of malicious content, or disruption of container deployment workflows. The vulnerability affects multiple versions of Quay, including 0, 2.14.0, and 3.12.0, indicating a long-standing issue or one present in multiple major releases. The CVSS 3.1 base score is 6.5 (medium severity), reflecting that the vulnerability is remotely exploitable without authentication or user interaction, with low complexity and impacts on confidentiality and integrity but not availability. No public exploits have been reported yet, but the flaw's nature makes it a significant risk for organizations relying on Quay for container image management, especially those using proxy caching to optimize image distribution. The vulnerability was published on May 6, 2025, and assigned by Red Hat, with enrichment from CISA, indicating recognition by major security entities. The lack of patch links suggests that fixes may be pending or not yet publicly released, emphasizing the need for immediate attention and mitigation.

For European organizations, the impact of CVE-2025-4374 can be substantial, particularly for those heavily reliant on containerized applications and DevOps pipelines using Project Quay as their image registry. Unauthorized Admin access to repositories can lead to the insertion of malicious container images, potentially compromising application confidentiality and integrity. This can result in supply chain attacks, where compromised images propagate through production environments, affecting critical infrastructure, financial services, healthcare, and government sectors. The vulnerability's remote exploitability without authentication increases the attack surface, allowing external threat actors or insider threats to escalate privileges easily. Disruption of container workflows or unauthorized data exposure could lead to regulatory compliance violations under GDPR and other European data protection laws, resulting in legal and financial repercussions. Organizations using proxy caching to optimize network efficiency are particularly at risk, as the flaw specifically targets this configuration. The absence of known exploits currently provides a window for proactive defense but also means attackers may develop exploits soon, increasing urgency for mitigation.

European organizations should immediately audit their use of Project Quay, especially configurations involving proxy caching. Until patches are available, organizations should consider disabling proxy cache functionality or restricting image pulls to authenticated and authorized users only. Implement strict access controls and monitoring on repository creation events to detect unauthorized privilege escalations. Employ network segmentation and firewall rules to limit external access to Quay instances. Use container image signing and verification mechanisms to ensure image integrity and detect tampering. Regularly review and rotate credentials and API tokens associated with Quay to minimize the risk of abuse. Engage with the Project Quay vendor or community to obtain patches or updates addressing this vulnerability as soon as they are released. Additionally, integrate vulnerability scanning and runtime security tools in container environments to detect anomalous behavior stemming from compromised images. Maintain incident response plans tailored to container security incidents to enable rapid containment if exploitation occurs.