librenms-librenms/includes/html/pages/plugin.inc.php

<?php

use LibreNMS\Config;

$link_array = array('page' => 'plugin');

if ($vars['view'] == 'admin') {
    include_once Config::get('install_dir') . '/includes/html/pages/plugin/admin.inc.php';
    $pagetitle[] = 'Plugins';
} else {
    $pagetitle[] = $vars['p'];
    $plugin = dbFetchRow("SELECT `plugin_name` FROM `plugins` WHERE `plugin_name` = ? AND `plugin_active`='1'", [$vars['p']]);
    if (!empty($plugin)) {
        $plugin_path = Config::get('plugin_dir').'/'.$plugin['plugin_name'].'/'.$plugin['plugin_name'].'.inc.php';
        if (is_file($plugin_path)) {
            chdir(Config::get('install_dir') . '/html');
            include $plugin_path;
            chdir(Config::get('install_dir'));
            return;
        }
    }
    print_error('This plugin is either disabled or not available.');
}