URL spoofing bug (with iframes) in Microsoft Internet Explorer:
(11/02/2004)

There is a security bug in Microsoft Internet Explorer, which allows to
show any faked target-address in the status bar of the window.

The example below will display a faked URL ("http://www.microsoft.com/") in
the status bar of the window, if you move your mouse over the link. Click
on the link and IE will go to "http://www.google.com/" and NOT to
"http://www.microsoft.com/" .

HTML code for page #1 called "btf.htm":

<a href="http://www.microsoft.com/">
<iframe src="./btf-spoofing.htm" frameborder="0" scrolling="no" width="70"
height="25" marginheight="0" marginwidth="0"></iframe>
</a>


HTML code for page #2 called "btf-spoofing.htm":

<a href="http://www.google.com/" target="_top">Click here</a>


Save both codes as HTML files in the same directory and open "btf.htm" with
Microsoft Internet Explorer.


Description:
Microsoft Internet Explorer can not handle embedded frames with links
surrounded by an other link correct.
Successful exploitation allows a malicious web site to obfuscate URLs in
the status bar, even when javascript support has been disabled.

Affected software:
Microsoft Internet Explorer

Workaround:
Never follow links from untrusted sources. Or right-click on links ans
select "Properties" to see the real target. Or use Copy-and-Paste.


Tested in Microsoft Internet Explorer 6 SP1 (6.0.2800.1106) with all
patches installed on Windows 98. I see "http://www.microsoft.com/" in
status bar.
ONLY if I press tabulator-key 3x (to jump to next link) or click on the
link, then I can see correct info ("http://www.google.com/") in status bar.

My DLL versions:

MSHTML.DLL: 6.00.2800.1477
BROWSEUI.DLL: 6.00.2800.1596 (xpsp2.040919-1003)
SHDOCVW.DLL: 6.00.2800.1596 (xpsp2.040919-1003)
SHLWAPI.DLL: 6.00.2800.1584 (xpsp2.040720-1705)
URLMON.DLL: 6.00.2800.1475
WININET.DLL: 6.00.2800.1475


Regards,
Benjamin Tobias Franz
Germany