CVE-2025-4374: Red Hat Quay Auth Bypass Vulnerability

CVE-2025-4374 Overview

CVE-2025-4374 is a privilege assignment flaw in Red Hat Quay, an enterprise container image registry. When an organization is configured as a proxy cache, pulling an image that has not yet been mirrored triggers repository creation with excessive default permissions. The user or robot account initiating the pull receives Admin rights on the newly created repository. This behavior enables unintended control over cached repositories, including the ability to modify permissions and manage repository settings. The issue is categorized under [CWE-266: Incorrect Privilege Assignment] and affects Red Hat Quay deployments that rely on the proxy cache feature to mirror upstream images on demand.

Critical Impact
Users and robot accounts triggering the first pull of a non-mirrored image receive administrative permissions on the resulting repository, breaking least-privilege expectations in proxy cache organizations.

Affected Products

Red Hat Quay (container image registry)
Deployments using organizations configured as proxy caches
Repositories auto-created on first pull of a non-mirrored image

Discovery Timeline

2025-05-06 - CVE-2025-4374 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-4374

Vulnerability Analysis

Red Hat Quay supports a proxy cache feature that lets an organization mirror images from an upstream registry on demand. When a user or robot pulls an image that has not yet been cached, Quay creates the corresponding repository automatically. The flaw resides in the permission model applied during that automatic creation.

Instead of granting the requester a read-only or scoped role appropriate for a cache consumer, Quay assigns the Admin role on the newly created repository. Administrative permissions allow the account to change repository visibility, modify team access, delete tags, and alter mirroring configuration. In multi-tenant deployments, this breaks the isolation expected between consumers of a shared proxy cache organization.

The attack vector is network based and requires no user interaction beyond a standard docker pull or equivalent client action against the proxy cache endpoint. Exploitation depends on the target image not having been previously mirrored, so timing and image selection influence success.

Root Cause

The root cause is incorrect privilege assignment during on-demand repository provisioning in the proxy cache workflow. Quay does not apply a least-privilege default role for the account that triggers repository creation. This is classified as [CWE-266].

Attack Vector

An authenticated user or robot account with pull access to a proxy cache organization requests an image tag not yet mirrored. Quay creates the repository and assigns Admin to the requester. The account can then reconfigure the repository, grant access to additional identities, or tamper with cached content used by other workloads.

No verified public proof-of-concept code is available for this issue. Refer to the Red Hat CVE-2025-4374 Advisory and Red Hat Bugzilla #2364267 for authoritative technical details.

Detection Methods for CVE-2025-4374

Indicators of Compromise

Repositories created inside proxy cache organizations where a non-owner account holds the Admin role.
Audit log entries showing repository creation events immediately followed by permission grants to the initiating user or robot.
Unexpected changes to repository visibility, team membership, or mirror configuration inside proxy cache organizations.

Detection Strategies

Query the Quay API or database for repositories under proxy cache organizations and enumerate role assignments per user and robot account.
Alert when a robot account holds the Admin role on a repository it did not previously own.
Correlate image pull events with subsequent repository administrative actions performed by the same identity.

Monitoring Recommendations

Ingest Quay audit logs into a centralized log platform and monitor createRepo and changePermission event pairs from the same principal.
Track proxy cache organization activity for new repository creation rates that deviate from baseline pull patterns.
Review robot account permissions on a scheduled cadence to identify unexpected administrative rights.

How to Mitigate CVE-2025-4374

Immediate Actions Required

Apply the fixed Red Hat Quay release referenced in the Red Hat CVE-2025-4374 Advisory.
Audit all repositories in proxy cache organizations and revoke Admin rights from accounts that should hold read-only access.
Rotate credentials for robot accounts that may have been granted unintended administrative privileges.

Patch Information

Red Hat has published remediation guidance in the Red Hat CVE-2025-4374 Advisory. Track the associated Red Hat Bugzilla #2364267 for build versions and errata mapped to your Quay deployment channel.

Workarounds

Restrict who can pull through proxy cache organizations by scoping pull credentials to a minimal set of trusted users and robots.
Pre-mirror required images administratively so that on-demand repository creation does not occur for end users.
Periodically reconcile repository roles inside proxy cache organizations and remove any Admin grants that were not explicitly authorized.

bash

# Example: list repositories and permissions in a proxy cache organization using the Quay API
curl -sSH "Authorization: Bearer ${QUAY_OAUTH_TOKEN}" \
  "https://<quay-host>/api/v1/repository?namespace=<proxy-cache-org>" \
  | jq -r '.repositories[].name' \
  | while read repo; do
      echo "# ${repo}"
      curl -sSH "Authorization: Bearer ${QUAY_OAUTH_TOKEN}" \
        "https://<quay-host>/api/v1/repository/<proxy-cache-org>/${repo}/permissions/user/" \
        | jq '.permissions'
    done