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 = '
';
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@gulo.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