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PunBB BBCode IMG Tag Script Injection Vulnerability



ECHO_ADV_22$2005

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            PunBB BBCode IMG Tag Script Injection Vulnerability
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Author: y3dips
Date: August, 20th 2005
Location: Indonesia, Jakarta
Web: http://echo.or.id/adv/adv22-y3dips-2005.txt

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Affected software description:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Version: 1.2.6 and most likely below
url : http://punbb.org
Author: Rickard Andersson
Description:

PunBB is a fast and lightweight PHP powered discussion board. It is released 
under the GNU Public License. Its primary goal is to be a faster, smaller and 
less graphic alternative to otherwise excellent discussion boards such as 
phpBB, Invision Power Board or vBulletin. PunBB has fewer features than many 
other discussion boards, but is generally faster and outputs smaller pages.

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Vulnerabilities:
~~~~~~~~~~~~~~~~

According to the issue that affect PHPBB discovered by easyex recently at 
http://www.securityfocus.com/bid/14555/info , so it also affected in another 
bulletin board or forum that allow BBcode such as PunBB.

The issue is due to a failure of the application to properly sanitize 
user-supplied input in bbcode '[IMG]' tags included in a message or user 
signature (if allowed , default is off) .

Successful exploitation of this vulnerability could permit the injection of 
arbitrary HTML or script code into the browser of an unsuspecting user in the 
context of the affected site.


Exploit: 
~~~~~~~~

just post a message that include

[img]http://attacker.com/yuckfou.png[/img]

yuckfou.png is a folder , and include some "index.php" file

---- index.php ----

<?php
header("Location: http://target.com/punbb1.2.6/login.php?action=out&id=2";); ?>

---- eof ------

so , user with id=2 if open the topics with attacker message include will 
automatically "logout"

maybe some other interesting in command could put in "index.php" with admin 
priveledged *_^


THATS all

Fix
~~~

Vendor allready contacted but no responses

Shoutz:

~~~~~~~



~ m0by, the_day, comex, z3r0byt3, K-159, c-a-s-e, S`to @T echo/staff
~ waraxe , LINUX, Heintz , slimjim100 , lunix, easyex all member of waraxe

~ newbie_hacker@xxxxxxxxxxxxxxx ,

~ #e-c-h-o & #aikmel @DALNET

Contact:
~~~~~~~~

y3dips || echo|staff 
Homepage: http://y3dips.echo.or.id/