Re: Remote overflow in MSIE script action handlers (mshtml.dll)

[<c0redump () ackers org uk>]

Worked like a treat first time on IE 6.0.2900.2180.xpsp_sp2_gdr.050301-1519 
and exited with error:

"Unhandled exception at 0x7d56a08d in iexplore.exe: 0xC0000005: Access 
violation writing location 0x037c7eb8."

c0redump

----- Original Message ----- 
From: Michal Zalewski
To: Daniel Bonekeeper
Cc: bugtraq () securityfocus com ; vulnwatch () vulnwatch org ; 
full-disclosure () lists grok org uk
Sent: Thursday, March 16, 2006 9:13 PM
Subject: Re: Remote overflow in MSIE script action handlers (mshtml.dll)


On Thu, 16 Mar 2006, Daniel Bonekeeper wrote:

> BTW, tested the POC on MSIE (File Version = 6.00.2900.2180
> (xpsp_sp2_rtm.040803-2158)) with mshtml.dll (6.00.2900.2802
> (xpsp_sp2_gdr.051123-1230)) and it didn't worked.

Daniel followed up with me in private and confirmed that the PoC *did*
work for him when he followed certain additional instructions: because the
attack depends on memory layout and usage, to get consistent results, be
sure to close *all* MSIE windows, then go to Start -> Run... and type:

 iexplore http://lcamtuf.coredump.cx/iedie.html

That should crash the browser immediately, because there are no other
buffers nearby to "absorb" the initial fencepost. Still, if no dice, try
hitting 'Reload' a couple of times.

/mz