Operating System:



12 July 2006

Protect yourself against future threats.

Hash: SHA1

             AUSCERT External Security Bulletin Redistribution

                          ESB-2006.0455 -- [Win]
       MS06-036 Buffer Overrun in DHCP Client Service Vulnerability
                               12 July 2006


        AusCERT Security Bulletin Summary

Product:              DHCP Client Service
Publisher:            Microsoft
Operating System:     Windows Server 2003 x64 Edition
                      Windows Server 2003 Itanium SP1
                      Windows Server 2003 Itanium
                      Windows Server 2003 SP1
                      Windows Server 2003
                      Windows XP Professional x64 Edition
                      Windows XP SP 2
                      Windows XP SP 1
                      Windows 2000 SP 4
Impact:               Execute Arbitrary Code/Commands
Access:               Remote/Unauthenticated
CVE Names:            CVE-2006-2372

Original Bulletin:

- --------------------------BEGIN INCLUDED TEXT--------------------

MS06-036 Buffer Overrun in DHCP Client Service Vulnerability

Affected Software:
   - Microsoft Windows 2000 Service Pack 4
   - Microsoft Windows XP Service Pack 1
   - Microsoft Windows XP Service Pack 2
   - Microsoft Windows XP Professional x64 Edition
   - Microsoft Windows Server 2003
   - Microsoft Windows Server 2003 Service Pack 1
   - Microsoft Windows Server 2003 for Itanium-based Systems
   - Microsoft Windows Server 2003 with SP1 for Itanium-based Systems
   - Microsoft Windows Server 2003 x64 Edition

Non-Affected Software:
   - Microsoft Windows 98
   - Microsoft Windows 98 Second Edition (SE)
   - Microsoft Windows Millennium Edition (Me)

There is a remote code execution vulnerability in the DHCP Client service
that could allow an attacker who successfully exploited this vulnerability
to take complete control of the affected system.

Mitigating Factors
- ------------------	
For an attack to be successful the attacker must send the affected host a
specially crafted DHCP response communication from the same network subnet.

- -----------
Microsoft has tested the following workarounds. Although these workarounds
will not correct the underlying vulnerability, they help block known attack

Use a static IP address
  To configure the system to use a static IP address follow these steps:

  1. Obtain a static IP address from your network administrator

  2. Click Start, and then click Control Panel and then click Network and
     Internet Connections.

  3. Right-click the connection on which you want to specify to use a static 
     IP address, and then click Properties.

  4. Select Internet Protocol (TCP/IP) and click Properties.

  5. On the General tab, click on the Use the following IP address and Use
     the following DNS server addresses radio buttons.

  6. Input your static IP address, subnet mask, default gateway, and DNS

  7. Click Ok twice.

  8. Repeat steps 3 through 7 for each of your network adapters.
Disable the DHCP Client service
  Disabling the DHCP Client service will help protect the affected system
  from attempts to exploit this vulnerability. To disable the DHCP Client
  service, follow these steps:

  1. Click Start, and then click Control Panel. Alternatively, point to
     Settings, and then click Control Panel.

  2. Double-click Administrative Tools.

  3. Double-click Services.

  4. Double-click DHCP Client.

  5. In the Startup type list, click Disabled.

  6. Click Stop, and then click OK.

You can also stop and disable the DHCP service by using the following
command at the command prompt:

  sc stop DHCP & sc config DHCP start= disabled

Impact of Workaround: If you disable the DHCP service, you cannot
                      automatically retrieve an IP address from a DHCP
                      Server. Without an IP address you will not be able to
                      connect to the network.

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:


If you believe that your computer system has been compromised or attacked in 
any way, we encourage you to let us know by completing the secure National IT 
Incident Reporting Form at:


Australian Computer Emergency Response Team
The University of Queensland
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.

Comment: http://www.auscert.org.au/render.html?it=1967