A critical missing authorization vulnerability in Anchor CMS allows any authenticated user to escalate their privileges to full administrator, posing a severe risk of complete system compromise.

The application fails to perform role-based access control checks on the admin/users/add and admin/users/edit endpoints. This flaw allows any authenticated user, regardless of their original role, to create new administrator accounts or modify the credentials of existing administrative users.

Successful exploitation of this vulnerability results in full administrative control over the Anchor CMS instance. An attacker can gain unauthorized access to sensitive site data, modify content, or potentially leverage the administrative interface to execute further malicious actions. Given the CVSS score of 8.8, this vulnerability is considered high severity, as it bypasses critical security boundaries and grants full control to unauthorized entities.

Immediate Action: Since a specific patch is not yet confirmed, administrators should restrict access to the admin panel to trusted networks only and closely audit existing user accounts for unauthorized additions or changes.

Proactive Monitoring: Monitor server access logs for POST requests directed at admin/users/add or admin/users/edit from non-administrative user accounts.

Compensating Controls: Deploy a Web Application Firewall (WAF) rule to block or challenge requests to administrative user management endpoints originating from unauthorized user roles.

Public Exploit Available: Yes, a published PoC exists (the vulnerability details and attack vectors are documented in the provided researcher write-up).

Due to the critical nature of this privilege escalation vulnerability, immediate containment is required. Organizations should prioritize restricting administrative access and auditing user accounts to identify any unauthorized modifications. Once the vendor releases an official security update, it must be applied immediately to remediate the underlying authorization flaw.