11 June 2010
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2010.0525 Vulnerability in Windows Help and Support Center Could Allow Remote Code Execution 11 June 2010 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Windows Help and Support Center Publisher: Microsoft Operating System: Windows XP Windows Server 2003 Impact/Access: Execute Arbitrary Code/Commands -- Remote with User Interaction Resolution: Mitigation CVE Names: CVE-2010-1885 Original Bulletin: http://www.microsoft.com/technet/security/advisory/2219475.mspx - --------------------------BEGIN INCLUDED TEXT-------------------- Microsoft Security Advisory (2219475) Vulnerability in Windows Help and Support Center Could Allow Remote Code Execution Published: June 10, 2010 Version: 1.0 General Information Executive Summary Microsoft is investigating new public reports of a possible vulnerability in the Windows Help and Support Center function that is delivered with supported editions of Windows XP and Windows Server 2003. This vulnerability could allow remote code execution if a user views a specially crafted Web page using a Web browser or clicks a specially crafted link in an e-mail message. Microsoft is aware that proof of concept exploit code has been published for the vulnerability. However, Microsoft is not currently aware of active attacks that use this exploit code or of customer impact at this time. Microsoft is actively monitoring this situation to keep customers informed and to provide customer guidance as necessary. We are actively working with partners in our Microsoft Active Protections Program (MAPP) to provide information that they can use to provide broader protections to customers. Upon completion of this investigation, Microsoft will take the appropriate action to help protect our customers. This may include providing a security update through our monthly release process or providing an out-of-cycle security update, depending on customer needs. Affected Software Windows XP Service Pack 2 and Windows XP Service Pack 3 Windows XP Professional x64 Edition Service Pack 2 Windows Server 2003 Service Pack 2 Windows Server 2003 x64 Edition Service Pack 2 Windows Server 2003 with SP2 for Itanium-based Systems Mitigating Factors Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of this issue. The following mitigating factors may be helpful in your situation: * In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. In addition, compromised Web sites and Web sites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit this vulnerability. In all cases, however, an attacker would have no way to force users to visit these Web sites. Instead, an attacker would have to convince users to visit the Web site, typically by getting them to click a link in an e-mail message or Instant Messenger message that takes users to the attacker's Web site. * The vulnerability cannot be exploited automatically through e-mail. For an attack to be successful a user must click a link listed within an e-mail message. * An attacker who successfully exploited this vulnerability could gain the same user rights as the local user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Workarounds Workaround refers to a setting or configuration change that does not correct the underlying issue but would help block known attack vectors before a security update is available. Microsoft has tested the following workarounds and states in the discussion whether a workaround reduces functionality: * Unregister the HCP Protocol Note Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or view the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Unregistering the HCP Protocol prevents this issue from being exploited on affected systems. Using the Interactive Method 1. Click Start, click Run, type Regedit in the Open box, and then click OK 2. Locate and then click the following registry key: HKEY_CLASSES_ROOT\HCP 3. Click the File menu and select Export 4. In the Export Registry File dialog box, enter HCP_Procotol_Backup.reg and click Save. Note This will create a backup of this registry key in the My Documents folder by default. 5. Press the Delete key on the keyboard to delete the registry key. When prompted to delete the registry key via the Confirm Key Delete dialog box, click Yes. * Using a Managed Deployment Script 1. Create a backup copy of the registry keys by using a managed deployment script that contains the following commands: Regedit.exe /e HCP_Protocol_Backup.reg HKEY_CLASSES_ROOT\HCP 2. Next, save the following to a file with a .REG extension, such as Disable_HCP_Protocol.reg: Windows Registry Editor Version 5.00 [-HKEY_CLASSES_ROOT\HCP] 3. Run the above registry script on the target machine with the following command from an elevated command prompt: Regedit.exe /s Disable_HCP_Protocol.reg Impact of Workaround: Unregistering the HCP protocol will break all local, legitimate help links that use hcp://. For example, links in Control Panel may no longer work. How to undo the workaround * Using the interactive method 1. Click Start, click Run, type Regedit in the Open box, and then click OK. 2. Click the File menu and select Import. 3. In the Import Registry File dialog box, select HCP_Procotol_Backup.reg and click Open. * Using a Managed Deployment Script Restore the original state by running the following command: Regedit.exe /s HCP_Protocol_Backup.reg - --------------------------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 email@example.com and we will forward your request to the appropriate person. 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If you have any questions or need further information, please contact them directly. 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: firstname.lastname@example.org 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 iD8DBQFMEXHd/iFOrG6YcBERAmviAJ9Kz0+mhQsT9i6XY3MPg7SuN4WQYQCfXrCD ycTS/GUI/+o5neYcBw61ySE= =/Z6m -----END PGP SIGNATURE-----