Onderwerp: RE : IE / Outlook / MS SHLWAPI Render - more trivial crash

Original message :

>Hola:
>Well, as it seems that is the Microsoft Crash mounth, let see another
one:
>---------------------------------
><html>
><form>
><input type crash>
></form>
></html>
>---------------------------------
>This will crash IE with the following error:
>"Unhandled exception in iexplore.exe (SHLWAPI.DLL): 0xC0000005: Access
>Violation"
>It's a null pointer overwrite, so it's not easly exploitable...

>This HTML also crash Outlook, Frontpage, and all the Microsoft programs
that >use the shlwapi.dll library to render web code.
>Plain HTML is a dangerous language

Added :

It also seems to crash explorer.exe when the .html file containing the
code is copied into any folder !!
It may work since windows is trying to create a view in Windows
explorer. Indeed, it doesn't work when the file is copied in the
desktop.

Tested on Windows XP with Office XP.

Technical details:

IE tries to compare the type of the input field to "HIDDEN", to see if it
should be rendered. When there is no type string, a null-pointer is used.

mshtml.dll calls shlwapi.dll#158 @ 0x636f0037 with a pointer to a static
unicode string "HIDDEN" and a null-pointer.
shlwapi.dll#158 does a case-insensitive comparison of two unicode strings:
it reads from address 0x0 because of the null-pointer and thus causes an
exception.
This is not exploitable, other then a DoS because there is no memory mapped
@ 0x0 and even if you could load something there, you could only compare it
to "HIDDEN" which gets you nowhere.

Berend-Jan Wever

----- Original Message -----
From: "Gervaize Maquard" <freestyler@tiscali.fr>
To: <bugtraq@securityfocus.com>
Sent: Tuesday, April 22, 2003 22:29
Subject: RE : IE / Outlook / MS SHLWAPI Render - more trivial crash


> Original message :
>
> >Hola:
> >Well, as it seems that is the Microsoft Crash mounth, let see another
> one:
> >---------------------------------
> ><html>
> ><form>
> ><input type crash>
> ></form>
> ></html>
> >---------------------------------
> >This will crash IE with the following error:
> >"Unhandled exception in iexplore.exe (SHLWAPI.DLL): 0xC0000005: Access
> >Violation"
> >It's a null pointer overwrite, so it's not easly exploitable...
>
> >This HTML also crash Outlook, Frontpage, and all the Microsoft programs
> that >use the shlwapi.dll library to render web code.
> >Plain HTML is a dangerous language
>
> Added :
>
> It also seems to crash explorer.exe when the .html file containing the
> code is copied into any folder !!
> It may work since windows is trying to create a view in Windows
> explorer. Indeed, it doesn't work when the file is copied in the
> desktop.
>
> Tested on Windows XP with Office XP.
>

> -----Original Message-----
> From: Gervaize Maquard [mailto:freestyler@tiscali.fr]
> Sent: Wednesday, April 23, 2003 12:00 AM
> To: bugtraq@securityfocus.com
> Subject: RE : IE / Outlook / MS SHLWAPI Render - more trivial crash
>
>
> Original message :
>
> >Hola:
> >Well, as it seems that is the Microsoft Crash mounth, let see another
> one:
> >---------------------------------
> ><html>
> ><form>
> ><input type crash>
> ></form>
> ></html>
> >---------------------------------
> >This will crash IE with the following error:
> >"Unhandled exception in iexplore.exe (SHLWAPI.DLL):
> 0xC0000005: Access
> >Violation" It's a null pointer overwrite, so it's not easly
> >exploitable...
>
> >This HTML also crash Outlook, Frontpage, and all the
> Microsoft programs
> that >use the shlwapi.dll library to render web code.
> >Plain HTML is a dangerous language
>
> Added :
>
> It also seems to crash explorer.exe when the .html file
> containing the code is copied into any folder !! It may work
> since windows is trying to create a view in Windows explorer.
> Indeed, it doesn't work when the file is copied in the desktop.
>
> Tested on Windows XP with Office XP.
>

Not only on winXP; it has the same effect on win2000 server and
advanced server; windows.NET advanced server & interprise server RC1;
RC2 & the release version. With office XP or 2000 or without them.
Of course you could delete the file through the command prompt.
Another interesting thing; in win2000 and winXP, the browser (
iexplore or explorer or ... ) hangs & shows the message that send this
error to microsoft & restart the browser.
In win.NET it crashes the browser & restarts it without any message.
But.....
After u log off & again log on; it now shows the messages to
you; one by one.
It shows the stability of .NET system that keeps the messages for u. )