phorum503.txt

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Vendor : Phorum  
URL : http://www.phorum.org  
Version : Phorum 5.0.3 Beta && Earlier  
Risk : Cross Site Scripting  
  
  
  
Description:  
Phorum is a web based message board written in PHP. Phorum is designed   
with high-availability and visitor ease of use in mind. Features such as   
mailing list integration, easy customization and simple installation make   
Phorum a powerful add-in to any website.  
  
  
  
Problem:  
Phorum have patched a good number of XSS (Cross Site Scripting) issues in   
the past, but there is still some work to be done regarding these issues   
before the final release of Phorum Version 5. The first issue I am going   
to talk about lies in "login.php" If you look at the HTML source code you   
should see two hidden variables. One called "f" which specifies the forum   
id, and one called "target" which specifies the location to take the user   
after they login. Unfortunately both of these values are taken directly   
from the value of HTTP_REFERER without any validation. While there is a   
global script in forum that checks for the <script> tag, it will allow for   
pretty much any thing else, and most of you know it is not hard to execute   
javascript inside of a tag which is allowed. This same vulnerability also   
exists in "register.php" And while not the exact same, a similar problem   
to these two exists in "profile.php" also. Below are some examples.  
  
login.php?HTTP_REFERER=[XSS]  
register.php?&HTTP_REFERER=[XSS]  
profile.php?id=2&action=edit&target=[XSS]  
  
  
  
Solution:  
The vendor was contacted and immediately responded, and will be releasing a   
fix soon. Thanks to Brian Moon and the rest of the forum dev team for such a   
quick response. It is appreciated. The original advisory can be located at  
the following location http://www.gulftech.org/03152004.php  
  
  
  
Credits:  
Credits go to JeiAr of the GulfTech Security Research Team.   
http://www.gulftech.org  
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