Date: 25 Apr 2004 08:25:25 -0000
From: JeiAr <security@...ftech.org>
To: bugtraq@...urityfocus.com
Subject: Multiple Vulnerabilities In OpenBB




Vendor  : OpenBB Group
URL     : http://www.openbb.com
Version : Open Bulletin Board 1.0.6 && Earlier
Risk    : Multiple Vulnerabilities



Description:
OpenBB is a fast, lightweight, powerful bulletin board written 
in PHP/MySQL. Main features include: full customization via styles 
templates, instant messaging, private messaging, categories, member 
ranks, poll based threads, moderation, BB codes, thread notifications, 
Avatars, member lists, private forums and more.  



Cross Site Scripting:
OpenBB is prone to Cross Site Scripting in multiple files. This may 
allow an attacker to run code in the context of a users browser, or 
used to harvest sensitive information from a user such as cookie 
information. Below are some examples of the XSS issues in OpenBB.

/member.php?action=login&redirect=[XSS]
/myhome.php?action=newmsg&to=blah[XSS]
/post.php?action=mail&TID=1[XSS]
/index.php?redirect=[XSS]



SQL Injection:
It may be possible for an attacker to execute arbitrary SQL queries 
due to user supplied input not being properly sanitized. Lets have
a look at some code from one of the affected files ... post.php

// Check to make sure they are not posting to a category
$query_type = new query($SQL, "SELECT type FROM ".$prefix."forum_display 
WHERE forumid = $FID");
$query_type->getrow();
$ftype = $query_type->field('type');

As we can see from this code, the $FID variable seems to get passed
directly to the query without being validated, thus allowing for 
an attacker to execute malicious queries. This is not the only 
vulnerable file though. Below are a list of similarly vulnerable 
files.

/board.php?FID=1[SQL]
/member.php?action=list&page=1&sortorder=[SQL]
/member.php?action=list&page=1&sortorder=username&perpage=[SQL]
/member.php?action=passwdsend&resetid=blah&id=2[SQL]
/search.php?&sortby=dateline&sort=DESC&q=open&forums%5B[SQL]%5D
/post.php?action=edit&page=1&PID=1[SQL]
/post.php?action=post&FID=1[SQL]

These files are prone to similar attacks because they allow input 
that has not been validated to be executed in the query. This can
be used for example to pull users password hashes.



Arbitrary Command Execution:
This is really in my opinion at least, a very fundamental flaw. As 
stated in the HTTP/1.1 RFC (RFC 2616 Section 9.1.1 "Safe Methods") 
no GET request should be used to make any significant actions. This 
however would not be such a big deal if there was some sort of auth 
key or session id in place to verify the validity of actions, but 
there isn't. In short all an attacker has to do is send an admin a 
pm, or make a malicious post with the desired command and the action 
will silently execute. For example below are some example administrative 
actions thatan attacker could include in an image tag or malicious link.

/cp_forums.php?do=remove&id=1
/cp_usergroup.php?do=remove&UGID=1
/cp_ipbans.php?action=do_delip&ipid=1

This kind of attack can also be used to run user and moderator 
commands as seen below. These are only examples, not all the 
possibilities.

/myhome.php?action=delmsg&box=inbox&id=all
/post.php?action=edit&PID=1&send=1&delete=yes
/moderator.php?action=announce&TID=1

OpenBB actually tries to  prevent these kind of attacks by filtering
out certain input as seen in /lib/codeparse.php but this does not 
work. Lets have a look at the code.

case 'img':
if(!preg_match('#^(http|https)://(.*?)\.(gif|jpg|jpeg|png)$#', $inside) )
$return = '[ invalid image ]';
else
$return = '<img src="' .str_replace('"', '', $inside). '" alt="User-Posted 
Image (tm)" border="0" />';
break;

All an attacker has to do in order to have the command executed 
successfully is make sure the url within the image tag ends with 
an allowed extension. This is not very safe at all because we can 
make up a variable, add a good extension and the code is still ran. 
For example

/post.php?action=edit&PID=1&send=1&delete=yes&image=blah.jpg

As we can see from the above examples, this issue can be used by a 
malicious person to all but completely sabotage a site running 
OpenBB. In the past I have seen phpBB for example deal with the same 
issue of using unsafe GET requests by limiting the bbcode to only 
allow images with a valid extension. However this is a bad idea 
because it does not solve the problem at all, and to this day all 
phpBB versions are vulnerable to having arbitrary posts deleted and 
more just by visiting a malicious web page or link. It is a serious 
issue and should be treated as such. It greatly impacts the security 
of a web application. Even using the POST method without an auth key 
or the like is a bad idea 
in my opinion.


Other Issues:
These other issues I am about to describe have been discovered by a 
guy named Manuel Lopez mantra@...o.org and asked me to include them 
in this OpenBB write up.

/* Snip */

Hi JeiAr, I am Manuel. 

I have just read your post in OpenBB.
At March 24 2004 I alert Stu about some vulnerabilities that I have found on 
March 20 2004, Stu 

tell me .. "A verson 1.0.7 will be released ASAP".
I was having in mind publishing an advisory as soon as Stu released the new 
version. 

/* Snip */

The issues are in the avatar feature and pm feature. From what I 
understand a user can read arbitrary PM's just by specifying the 
message id. For example the url might look something like this.

http://forum/myhome.php?action=readmsg&id=INT&box=inbox

Where "INT" is there would be an integer specifying the message ID. 
The other issue discovered by Manuel is the fact that you can upload 
any file as an avatar. While this does not allow for php, or server 
side code execution, it does allow for client side code (such as JS, 
VBS, etc) to be executed. The uploaded code will then be available at 
the following url once uploaded.

http://forum/avatars/[usernamehere]avatar_type

Once again, just want to specify the last two vulnerabilities were 
discovered by Manuel Lopez and not myself, he just asked if I would 
include them :)



Solution:
 Vendors were contacted many weeks ago and plan to release a fixed 
 version soon. Check the OpenBB website for updates and official 
 release details. 
 Original advisory can be found @ http://www.gulftech.org/04242004.php



Credits:
Credits go to JeiAr of the GulfTech Security Research Team. 
http://www.gulftech.org

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