Home page logo

bugtraq logo Bugtraq mailing list archives

RE: Disclosure of file system information in Mozilla Firefox and Opera Browser:
From: "Thor Larholm" <thor () pivx com>
Date: Mon, 6 Dec 2004 13:36:57 -0800

This is not a vulnerability, it is expected behavior.

Mozilla shares the same zone design as IE which means that a file from
the local file zone can read any other file from the local file zone.
You cannot use this approach to read a local file from another zone such
as the Internet zone. From the Internet zone, you can also only read the
content of files from the same zone, same protocol and same domain.

I agree that Mozilla has implemented quite a lot of proprietary IE
extensions which it should have not done, however reading the innerHTML
of an element through document.all does not circumvent the traditional
zone security checks already in place.

If you can find a cross zone scripting vulnerability in Mozilla this
becomes relevant, however in that case you would be better off jumping
into a chrome:// document from which you can execute arbitrary commands.


Thor Larholm
Senior Security Researcher
PivX Solutions
23 Corporate Plaza #280
Newport Beach, CA 92660
thor () pivx com
Stock symbol: (PIVX.OB)
Phone: +1 (949) 231-8496
PGP: 0x4207AEE9
B5AB D1A4 D4FD 5731 89D6  20CD 5BDB 3D99 4207 AEE9

PivX defines a new genre in Desktop Security: Proactive Threat

-----Original Message-----
From: Giovanni Delvecchio [mailto:badpenguin79 () hotmail com] 
Sent: Wednesday, December 01, 2004 5:15 PM
To: bugtraq () securityfocus com
Subject: Disclosure of file system information in Mozilla Firefox and
Opera Browser:

Title: Disclosure of file system information in Mozilla Firefox and

I don't know if it could be considered really a security problem, anyway

i'll try to explain my ideas.
Sorry for my bad english.

Author: Giovanni Delvecchio

Bug: Disclosure of file system information

Applications affected:

- Firefox 1.0
- Mozilla 1.7
- Opera 7.54 (*)

( maybe also previous versions )

Tested versions:

- Firefox 1.0 on Linux and Windows
- Mozilla 1.7 on Windows
- Opera 7.51,..7.54 on Linux

The content of this advisory could be applied also to other browsers, i
checked just Mozilla, Firefox,Opera and Microsoft Internet Explorer.
Microsoft Internet Explorer seems not to be affected.

Bug Description:
A problem exist in some browsers where a frame can gain access to
of another frame or iframe.
An application of this bug could be the possibility to disclose local 
directory structure.


------ begin code.htm -----


<body onLoad="

  //send list_files at malicious_server


<iframe name="local_files" src="file:///home/" height=0



------ end of code.htm -------

A malicious server could obtain the content of /home/ directory ( or 
c:\Document and Setting\ for windows system  ) and so know a set of 
usernames present on system target.
Moreover, colud be possible know if a particolar program is installed on

target system for a succesive attack.

Anyway it cannot be exploited "directly" by a remote site, but only if
page is opened from a local path ( file://localpath/code.htm),  since
iframe "local_files" belongs to a local domain.

Note: with Internet Explorer code.htm doesn't work even in local.

Possible Remote Exploitation:

How could a malicious remote user exploit it ?

After that the user "victim" has required
if malicious_server responds with a page containing an unknown
field ( for example text/html. ,note the dot) ,the browser will show a 
dialog window with some options (open, save, cancel). Choosing "Open" to

view this page, it will be downloaded and opened in local ; javascript
will be executed in local context.
Obviously, if user chooses to save and after open it the result is

(*) For Opera this  method of remote exploitation requires that opera
be setted as Default Application in "handler for saved files" whether
user choose "Open" in the dialog window.

No solution at the moment

Vendor notice
24th November 2004: I have contacted mozilla by security () mozilla org
and Opera by its bug track page at https://bugs.opera.com/wizard/

No response from both at the moment.

Best regards,

Giovanni Delvecchio

Personalizza MSN Messenger con sfondi e fotografie! 

  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]