The WP Directorybox Manager plugin for WordPress is vulnerable to authentication bypass in versions up to, and including, 2.5. This is due to incorrect authentication in the wp_dp_enquiry_agent_contact_form_submit_callback function. This makes it possible for unauthenticated attackers to log in as any existing user on the site, such as an administrator, if they have access to the username.
A product requires authentication, but the product has an alternate path or channel that does not require authentication.