-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 National Cyber Alert System Technical Cyber Security Alert TA08-352A Microsoft Internet Explorer Data Binding Vulnerability Original release date: December 17, 2008 Last revised: -- Source: US-CERT Systems Affected * Microsoft Internet Explorer * Microsoft Outlook Express * Other software that uses Internet Explorer components to render documents Overview Microsoft Internet Explorer contains an invalid pointer vulnerability in its data binding code, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system. Exploit code for this vulnerability is publicly available and is being actively exploited. I. Description Microsoft Internet Explorer contains an invalid pointer vulnerability in its data binding code. When Internet Explorer renders a document that performs data binding, it may crash in a way that is exploitable to run arbitrary code. Any program that uses Internet Explorer's MSHTML layout engine, such as Outlook Express, may be at risk. Further details are available in US-CERT Vulnerability Note VU#493881. II. Impact By convincing a user to view a specially crafted document that performs data binding (e.g., a web page or email message or attachment), an attacker may be able to execute arbitrary code with the privileges of the user. III. Solution Apply an update This issue is addressed in Microsoft Security Bulletin MS08-078. This update provides new versions of mshtml.dll and wmshtml.dll, depending on the target operating system. More details are available in Microsoft Knowledge Base Article 960714. Disable Active Scripting This vulnerability can be mitigated by disabling Active Scripting in the Internet Zone, as specified in the Securing Your Web Browser document. Note that this will not block the vulnerability. IE still may crash when parsing specially crafted content. Disabling Active Scripting will mitigate a common method used to achieve code execution with this vulnerability. Enable DEP in Internet Explorer 7 Enabling DEP in Internet Explorer 7 on Windows Vista can help mitigate this vulnerability by making it more difficult to achieve code execution using this vulnerability. Additional workarounds Microsoft Security Bulletin MS08-078 provides additional details for the above workarounds, as well as other workarounds not listed here. These workarounds are further explained in the Microsoft SWI Blog. IV. References * Microsoft Security Bulletin MS08-078 - <https://www.microsoft.com/technet/security/bulletin/ms08-078.mspx> * MS08-078: Security update for Internet Explorer - <http://support.microsoft.com/kb/960714> * Microsoft Security Advisory (961051) - <http://www.microsoft.com/technet/security/advisory/961051.mspx> * Update on Internet Explorer 7, DEP and Adobe Software - <http://blogs.msdn.com/michael_howard/archive/2006/12/12/update-on-internet-explorer-7-dep-and-adobe-software.aspx> * Data Binding - <http://msdn.microsoft.com/en-us/library/ms531388(vs.85).aspx> * MSHTML Reference - <http://msdn.microsoft.com/en-us/library/aa741317.aspx> * US-CERT Vulnerability Note VU#493881 - <http://www.kb.cert.org/vuls/id/493881> * Securing Your Web Browser - <https://www.us-cert.gov/reading_room/securing_browser/#Internet_Explorer> ____________________________________________________________________ The most recent version of this document can be found at: <http://www.us-cert.gov/cas/techalerts/TA08-352A.html> ____________________________________________________________________ Feedback can be directed to US-CERT Technical Staff. Please send email to <cert@xxxxxxxx> with "TA08-352A Feedback VU#493881" in the subject. ____________________________________________________________________ For instructions on subscribing to or unsubscribing from this mailing list, visit <http://www.us-cert.gov/cas/signup.html>. ____________________________________________________________________ Produced 2008 by US-CERT, a government organization. Terms of use: <http://www.us-cert.gov/legal.html> ____________________________________________________________________ Revision History December 17, 2008: Initial release -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iQEVAwUBSUloq3IHljM+H4irAQJ5WggAilfQXBGc2UPVScZTIA81uf0dloPwzgJF xM5M5r0a5j8Km5g5mHdhzqs4Ni1DY0enftvm6JeagUmOzVPzOGemqXxTeAx/G6ZD ttW687bsX9OdDJ2cmq6EixRwgVPR6kVnSK5s/MLw8yYWg7RS0lY0Mrc42QUL2GXR KKBb3redelGZ6Szm5PKOcumYSP9bsQtxOqGZUx+d3l9cDeIDPn3c2aHFSkPP5mGr LyEEqXw5+ifpx6v1gGyRyFOtFHP2QBSOOrnt05S0KTuoBJQ9QtyC9TEyGVwWjeq8 68BuGiOakwNdsjpFLLjW4W34N3oXnGFKh6jXAi4KW3d9wcIidZj0+w== =T3zy -----END PGP SIGNATURE-----