UsersWP <= 1.2.78 - Unauthenticated Account Access via Predictable Dummy User Password Disclosed through Registration Form Hash

Overview

The UsersWP – Front-end login form, User Registration, User Profile & Members Directory plugin for WordPress is vulnerable to unauthorized account access via Use of Predictable Password in all versions up to, and including, 1.2.78 The vulnerability exists because get_dummy_user_passowrd() derives the shared password for all 25 built-in dummy user accounts as the first 15 characters of substr(hash('SHA256', AUTH_KEY . site_url()), 0, 25), while the full 25-character value of that same hash is simultaneously embedded in the hidden uwp_register_hash field rendered on every registration form response — reachable without authentication via both the public /register/ page and the wp_ajax_nopriv_uwp_ajax_register_form AJAX handler, even when user registration is disabled. This makes it possible for unauthenticated attackers to recover the dummy user password directly from a single HTTP request and use it to authenticate as any of the 25 built-in dummy accounts (such as antawn, chynna, or kiki) through wp-login.php, potentially achieving privilege escalation if any dummy account holds an elevated role. Exploitation requires that an administrator has previously created dummy users via the plugin's Tools page.

Affected

• userswp_front-end_login_form_user_registration_user_profile_members_directory_plugin_for_wp <= 1.2.78

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.