Re: [WEB SECURITY] RE: Universal PDF XSS After Party(posible solution)

[RSnake <rsnake () shocking com>]

Be careful using either of those.  REQUEST_URI can contain anything:

http://example.com/file.pdf?whatever#vectorgoeshere

For that example the request URI will be ..pathto..file.pdf?whatever
which does not match "\.pdf$".  Likewise the second one has issues,
including the fact that referrers are not always present (Zonelabs Zone
Alarm Pro, and both Norton Internet Security and Norton Personal
Firewall).  Also, referrers are spoofable using Flash.
http://ha.ckers.org/blog/20060725/forging-http-request-headers-with-flash/
(hat tip to Amit).


-RSnake
http://ha.ckers.org/
http://sla.ckers.org/
http://ha.ckers.org/fierce/

On Thu, 4 Jan 2007, Noe Espinoza M. wrote:

> We need to force to the users do download  the pdf files
>
> And we can add to the httpd.conf or .htaccess the next code
>
> SetEnvIf Request_URI "\.pdf$" requested_pdf=pdf
> Header add Content-Disposition "Attachment" env=requested_pdf
>
>
> Other solution is protect our pdf files to external links (hotlinking)
>
> Add in .htacces
>
> RewriteEngine on
> RewriteCond %{HTTP_REFERER} !^$
> RewriteCond %{HTTP_REFERER} !^http://([-a-z0-9]+\.)?example\.com[NC]
> RewriteRule .*\.(pdf)$ http://www.example.com/images/noexternal.gif [R,NC,L]
>
>
> Source from
> http://seguinfo.blogspot.com/2007/01/hacking-con-browser-plugins.html
>
>
>
> -----Mensaje original-----
> De: pdp (architect) [mailto:pdp.gnucitizen () googlemail com]
> Enviado el: jueves, 04 de enero de 2007 7:17
> Para: full-disclosure () lists grok org uk; bugtraq () securityfocus com; Web
> Security
> Asunto: Universal PDF XSS After Party
>
> Everybody knows about it. Everybody talks about it. We had a nice
> party. It is time for estimating the damages. In this article I will
> try to show the impact of the Universal PDF XSS vulnerability by
> explaining how it can be used in real life situations.
>
> http://www.gnucitizen.org/blog/universal-pdf-xss-after-party/
>
> --
> pdp (architect) | petko d. petkov
> http://www.gnucitizen.org