Add optional referer check to prevent CSRF in GET requests

thomascube

2011-02-08 a77cf2292b1b5e010172b572f618aef78795456b

Add optional referer check to prevent CSRF in GET requests

 CHANGELOG

@@ -1,6 +1,7 @@
CHANGELOG Roundcube Webmail
===========================

- Security: add optional referer check to prevent CSRF in GET requests
- Fix email_dns_check setting not used for identities/contacts (#1487740)
- Fix ICANN example addresses doesn't validate (#1487742)
- Security: protect login form submission from CSRF

 config/main.inc.php.dist

@@ -212,6 +212,9 @@
// check client IP in session athorization
$rcmail_config['ip_check'] = false;

// check referer of incoming requests
$rcmail_config['referer_check'] = false;

// this key is used to encrypt the users imap password which is stored
// in the session record (and the client cookie if remember password is enabled).
// please provide a string of exactly 24 chars.

 index.php

@@ -190,6 +190,14 @@
    $OUTPUT->show_message('invalidrequest', 'error');
    $OUTPUT->send($RCMAIL->task);
  }

  // check referer if configured
  if (!$request_check_whitelist[$RCMAIL->action] && $RCMAIL->config->get('referer_check') && !rcube_check_referer()) {
    raise_error(array(
      'code' => 403,
      'type' => 'php',
      'message' => "Referer check failed"), true, true);
  }
}

// handle special actions

 program/include/main.inc

@@ -5,7 +5,7 @@
 | program/include/main.inc                                              |
 |                                                                       |
 | This file is part of the Roundcube Webmail client                     |
 | Copyright (C) 2005-2009, The Roundcube Dev Team                       |
 | Copyright (C) 2005-2011, The Roundcube Dev Team                       |
 | Licensed under the GNU GPL                                            |
 |                                                                       |
 | PURPOSE:                                                              |
@@ -1265,6 +1265,19 @@


/**
 * Check whether the HTTP referer matches the current request
 *
 * @return boolean True if referer is the same host+path, false if not
 */
function rcube_check_referer()
{
  $uri = parse_url($_SERVER['REQUEST_URI']);
  $referer = parse_url(rc_request_header('Referer'));
  return $referer['host'] == rc_request_header('Host') && $referer['path'] == $uri['path'];
}


/**
 * @access private
 * @return mixed
 */

 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) 2005-2010, The Roundcube Dev Team                       |
 | Copyright (C) 2005-2011, The Roundcube Dev Team                       |
 | Licensed under the GNU GPL                                            |
 |                                                                       |
 | PURPOSE:                                                              |
@@ -47,6 +47,13 @@
                   "Please contact your server-administrator.";
}

// forbidden due to request check
else if ($ERROR_CODE==403) {
  $__error_title = "REQUEST CHECK FAILED";
  $__error_text  = "Access to this service was denied due to failing security checks!<br />\n".
                   "Please contact your server-administrator.";
}

// failed request (wrong step in URL)
else if ($ERROR_CODE==404) {
  $__error_title = "REQUEST FAILED/FILE NOT FOUND";