Fix path traversal vulnerability in setting a skin (#1490620)

Aleksander Machniak

2015-12-22 21b523c29b2d022f27c5c730d3afd394aff5cd0f

 program/include/rcmail_output_html.php

@@ -153,6 +153,17 @@
     */
    public function set_skin($skin)
    {
        // Sanity check to prevent from path traversal vulnerability (#1490620)
        if (strpos($skin, '/') !== false || strpos($skin, "\\") !== false) {
            rcube::raise_error(array(
                    'file'    => __FILE__,
                    'line'    => __LINE__,
                    'message' => 'Invalid skin name'
                ), true, false);

            return false;
        }

        $valid = false;
        $path  = RCUBE_INSTALL_PATH . 'skins/';

@@ -167,6 +178,8 @@
            }
            $valid = !$skin;
        }

        $skin_path = rtrim($skin_path, '/');

        $this->config->set('skin_path', $skin_path);
        $this->base_path = $skin_path;
@@ -870,17 +883,17 @@
                    $attrib['name'] = $this->eval_expression($attrib['expression']);

                if ($attrib['name'] || $attrib['command']) {
                    // @FIXME: 'noshow' is useless, remove?
                    if ($attrib['noshow']) {
                        return '';
                    }

                    $vars = $attrib + array('product' => $this->config->get('product_name'));
                    unset($vars['name'], $vars['command']);

                    $label   = $this->app->gettext($attrib + array('vars' => $vars));
                    $quoting = !empty($attrib['quoting']) ? strtolower($attrib['quoting']) : (rcube_utils::get_boolean((string)$attrib['html']) ? 'no' : '');

                    // 'noshow' can be used in skins to define new labels
                    if ($attrib['noshow']) {
                        return '';
                    }

                    switch ($quoting) {
                        case 'no':
                        case 'raw':