Fix HTTP User-Agent XSS vulnerability (#1488737)

program/steps/utils/error.inc

@@ -5,7 +5,7 @@
  | program/steps/utils/error.inc                                         |
  |                                                                       |
  | This file is part of the Roundcube Webmail client                     |
- | Copyright (C) 2005-2011, The Roundcube Dev Team                       |
+ | Copyright (C) 2005-2012, The Roundcube Dev Team                       |
  |                                                                       |
  | Licensed under the GNU General Public License version 3 or            |
  | any later version with exceptions for skins & plugins.                |
@@ -23,11 +23,11 @@ $rcmail = rcmail::get_instance();
 
 // browser is not compatible with this application
 if ($ERROR_CODE==409) {
-  $user_agent = $_SERVER['HTTP_USER_AGENT'];
+  $user_agent = htmlentities($_SERVER['HTTP_USER_AGENT']);
   $__error_title = 'Your browser does not suit the requirements for this application';
   $__error_text = <<<EOF
 <i>Supported browsers:</i><br />
-&raquo; &nbsp;Microsoft Internet Explorer 6+<br />
+&raquo; &nbsp;Microsoft Internet Explorer 7+<br />
 &raquo; &nbsp;Mozilla Firefox 3+<br />
 &raquo; &nbsp;Chrome 10+<br />
 &raquo; &nbsp;Safari 4+<br />