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

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.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CWE: CWE-287