Ticket #40888: 40888.patch

src/wp-login.php

@@ -285 +285 @@
 function retrieve_password() {
         $errors = new WP_Error();
 
-        if ( empty( $_POST['user_login'] ) ) {
+        if ( ! is_string ($_POST['user_login'] ) ) {
+                $errors->add('username_not_string', __('<strong>ERROR</strong>: Enter a string value of username or email address.'));
+        } elseif ( empty( $_POST['user_login'] ) ) {
                 $errors->add('empty_username', __('<strong>ERROR</strong>: Enter a username or email address.'));
         } elseif ( strpos( $_POST['user_login'], '@' ) ) {
                 $user_data = get_user_by( 'email', trim( wp_unslash( $_POST['user_login'] ) ) );
@@ -528 +530 @@
 
         login_header(__('Lost Password'), '<p class="message">' . __('Please enter your username or email address. You will receive a link to create a new password via email.') . '</p>', $errors);
 
-        $user_login = isset($_POST['user_login']) ? wp_unslash($_POST['user_login']) : '';
+        $user_login = isset($_POST['user_login']) && is_string($_POST['user_login']) ? wp_unslash($_POST['user_login']) : '';
 
 ?>
 
@@ -698 +700 @@
         $user_login = '';
         $user_email = '';
         if ( $http_post ) {
-                $user_login = isset( $_POST['user_login'] ) ? $_POST['user_login'] : '';
+                $user_login = isset( $_POST['user_login'] ) && is_string( $_POST['user_login']) ? $_POST['user_login'] : '';
                 $user_email = isset( $_POST['user_email'] ) ? wp_unslash( $_POST['user_email'] ) : '';
                 $errors = register_new_user($user_login, $user_email);
                 if ( !is_wp_error($errors) ) {