[Full-disclosure] New (19.10.05) MS-IE Url Spoofing bug (by K-Gen).

2005-10-20T00:00:00
ID SECURITYVULNS:DOC:9989
Type securityvulns
Reporter Securityvulns
Modified 2005-10-20T00:00:00

Description

New (19.10.05) MS-IE Url Spoofing bug (by K-Gen).

Gr337s .. I (K-Gen) have found a new (I think..) URL spoofing bug in IE.

Affected : All MS-IE Browsers (Win XP SP2 as well).

This allows a malicious website to host a specially crafted A HREF tag that shows to the user as a link to one location, but actually redirects to another. This can be used in Phishing scams and other malicious attacks.

The basic idea here is to write a geniune <a href=""> </a>tag but include an onClick event handeler that will redirect (window.location="";) to another page. The next example won't work:

<a href="http://microsoft.com" onClick="window.location='http://google.com';">Microsoft</a>

Probably there is some protection in IE .. but not enough :)

If we try the next thing:

<a href="http://microsoft.com" onClick="alert()">Microsoft</a>

An alert WILL pop-up before redirecting. The same thing will happen to the document.write(""); method, it will execute before redirection.

Hence, the next Proof of Concept:

<a href="http://microsoft.com" onClick="document.write(unescape('%3cscript%3ewindow.location=%27http://google.com%27%3c/script%3e'))">Microsoft</a>

Put the code into an HTML page and see for yourself. In the status bar and in the properties the link appears as http://microsoft.com , but if you click on the link it will redirect you to http://google.com .

I used unescape becuse characters like < > and ' cause run-time errors...

This is not extremely critical as the old %01@ bug (That still works on my IE sp1 :lol:), becuase It does not obscure the real link in the Address bar, but i bet there will be a PoC for this one too, sooner or later...

Have a Nice Day. K-Gen


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