New API: User List API Leaks Root User Access Token Leading to Privilege Escalation

Vulnerability Information

• Product: new-api
• Affected versions: versions before v1.0.0-rc.7 that serialize User.AccessToken as access_token; the issue was confirmed in v0.12.14
• Patched version: v1.0.0-rc.7
• Fixed commit: 0936e2504655a5cbf7bc3c388f6d3e2bb24916d3
• Type: Information Disclosure / Privilege Escalation

Description

In affected versions of new-api, the admin user list and user lookup APIs can return the access_token field for users, including the root user. An authenticated admin user can call endpoints such as GET /api/user/ to retrieve user records. Because access tokens function as bearer credentials for API authentication, leaking the root user's access token allows an admin user to authenticate as root and access root-only endpoints such as system configuration APIs.

This bypasses the intended role boundary between admin users and the root user and can result in privilege escalation to full system control.

Root Cause

The User.AccessToken field was serialized as json:"access_token" in affected versions. User management APIs returned User model objects directly after omitting only the password field from database queries, so JSON serialization could include access_token in API responses.

Affected code patterns include user list, user search, and user detail paths that use Omit("password") without preventing access_token from being serialized.

Impact

• An authenticated admin user may obtain the root user's access token.
• The attacker may impersonate the root user and access root-only APIs.
• The attacker may modify system settings, payment settings, OAuth/SMTP-related configuration, and other sensitive platform options.
• Access tokens for other users may also be exposed, enabling user impersonation.

Remediation

Upgrade to v1.0.0-rc.7 or later. The fix changes User.AccessToken to use json:"-", preventing the field from being serialized in API responses.

Operators should also rotate any root or user access tokens that may have been exposed before upgrading, especially if untrusted admin users had access to user management APIs.