Ticket #39645: 39645.2.diff

wp-includes/user.php

@@ -3089 +3089 @@
         // Check the username.
         if ( '' === $sanitized_user_login ) {
                 $errors->add( 'empty_username', __( '<strong>Error</strong>: Please enter a username.' ) );
+        } 
+        // Don't let somebody fake an admin account
+          elseif ( lcfirst( $sanitized_user_login ) == 'admin' ) {      
+                $errors->add( 'invalid_username', __( '<strong>Error</strong>: You are not allowed to use this username for security reasons.' ) );
         } elseif ( ! validate_username( $user_login ) ) {
                 $errors->add( 'invalid_username', __( '<strong>Error</strong>: This username is invalid because it uses illegal characters. Please enter a valid username.' ) );
                 $sanitized_user_login = '';