The Primakon Pi Portal 1.0.18 API /api/V2/pp_udfv_admin endpoint, fails to perform necessary server-side validation. The administrative LoginAs or user impersonation feature is vulnerable to a access control failure. This flaw allows any authenticated low-privileged user to execute a direct PATCH request, enabling them to impersonate any other arbitrary user, including application Administrators. This is due to a Broken Function Level Authorization failure (the function doesn't check the caller's privilege) compounded by an Insecure Design that permits a session switch without requiring the target user's password or an administrative token and only needs email of user.