Georgi Guninski security advisory #28, 2000



IE 5.x/Outlook allows executing arbitrary programs using .chm files and

temporary internet files folder



Systems affected:

IE 5.5/Outlook/Outlook Express - probably other versions, have not

tested



Risk: High

Date: 20 October 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:



There is a security vulnerability in IE 5.5/Outlook/Outlook Express

which allows

executing arbitratrary programs using .chm files and revealing the

location of

temporary internet files folder. This may lead to taking full control

over user's computer.



Details:

I reported a similar vulnerability regarding .chm files sometime ago and

Microsoft fixed it

by allowing .chm files to run programs only if the .chm was loaded from

the local file system.

But it is possible to find the temporary internet files folder - there

are several folders with

random names.

The following HTML code: