12 July 2006
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- 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: http://www.microsoft.com/technet/security/Bulletin/MS06-036.mspx - --------------------------BEGIN INCLUDED TEXT-------------------- MS06-036 Buffer Overrun in DHCP Client Service Vulnerability CVE-2006-2372 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. Workarounds - ----------- Microsoft has tested the following workarounds. Although these workarounds will not correct the underlying vulnerability, they help block known attack vectors. 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 servers. 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 firstname.lastname@example.org 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. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 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: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: email@example.com 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. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBRLRoFCh9+71yA2DNAQJmpwQAnvH7bmqQF5nqmmsxVXZWPt2T0oi4Yk9f LU20YWxBFk87HcT0Jg0n0hsmtVvyZupt6PvhdHvZI3x8kmXxn0MMBbiwTgrUynzX rqLx/YfmJjzDOd08iMQafmCBb8WZ0VMGWsyNahCEsmS8+g2yJE5fisN7y4ceggxC HkugnzGpwd0= =YVex -----END PGP SIGNATURE-----