Membership Plugin – Kadence Memberships < 4.0.1 - Unauthenticated Password Reset Link Poisoning to Account Takeover

Description

The plugn is vulnerable to password reset link poisoning leading to account takeover due to the legacy lost-password handler rc_process_lost_password_form() consuming the attacker-controlled rc_redirect POST parameter into two unvalidated sinks in legacy/includes/forms.php: wp_redirect( esc_url( $_POST['rc_redirect'] ) . ... ) at line 243, and add_query_arg( array( 'key' => $key, 'login' => ... ), $_POST['rc_redirect'] ) inside rc_send_password_reset_email() at line 306. The nonce required to reach the handler is broadcast by the public [login_form] shortcode at line 207 to any anonymous visitor. This makes it possible for unauthenticated attackers to issue a password-reset request for any account (including administrators) whose reset email body points the victim at an attacker-controlled host carrying a valid reset key/login. When the victim clicks the link, the reset key leaks to the attacker, who can replay it against the legitimate site to complete account takeover.