Vulnerability in widget Flash Tag Cloud for Blogsa and other ASP.NET engines

["MustLive" <mustlive@xxxxxxxxxxxxxxxxxx>]

Hello Bugtraq!

I want to warn you about security vulnerability in Flash Tag Cloud control
for ASP.NET.

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Advisory: Vulnerability in widget Flash Tag Cloud for Blogsa and other
ASP.NET engines
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URL: http://websecurity.com.ua/4213/
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Affected products: all versions of Flash Tag Cloud control for ASP.NET, all
versions of Flash Tag Cloud for Blogsa and other ASP.NET engines.
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Timeline:

10.05.2010 - found vulnerability.
19.05.2010 - disclosed at my site.
20.05.2010 - informed developers.
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Details:

This is Cross-Site Scripting vulnerability. Which I found in Flash Tag Cloud
control for ASP.NET (http://flashtagcloud.codeplex.com) on web sites with
Blogsa engine, but any ASP-sites with Flash Tag Cloud control and other
ASP.NET engines with this widget can be vulnerable.

This XSS is similar to XSS vulnerability in WP-Cumulus and other web
applications which I already reported to security mailing lists, because
it's using tagcloud.swf made by author of WP-Cumulus. About millions of
flash files tagcloud.swf which are vulnerable to XSS attacks I mentioned in
my article XSS vulnerabilities in 34 millions flash files
(http://www.webappsec.org/lists/websecurity/archive/2010-01/msg00035.html).

XSS:

http://site/Widgets/FlashTagCloud/tagcloud.swf?mode=tags&tagcloud=%3Ctags%3E%3Ca+href='javascript:alert(document.cookie)'+style='font-size:+40pt'%3EClick%20me%3C/a%3E%3C/tags%3E

Code will execute after click. It's strictly social XSS.

Also it's possible to conduct (like in WP-Cumulus) HTML Injection attack,
including in those flash files which have protection (in flash files or via
WAF) against javascript and vbscript URI in parameter tagcloud.

HTML Injection:

http://site/Widgets/FlashTagCloud/tagcloud.swf?mode=tags&tagcloud=%3Ctags%3E%3Ca+href='http://websecurity.com.ua'+style='font-size:+40pt'%3EClick%20me%3C/a%3E%3C/tags%3E

Best wishes & regards,
MustLive
Administrator of Websecurity web site
http://websecurity.com.ua