Vulnerability Note VU#320516

Windows Media Player 9 ActiveX control does not adequately validate access to Windows Media Library

The Windows Media Player 9 Series ActiveX control uses the Windows Media Player public object model, and provides access to the media library under certain conditions. The Windows Media Player 9 Series ActiveX control is a scriptable component, meaning that script code can be used to invoke or control it. The ActiveX control does not properly validate requests made by script to access the Media Library.

Apply the appropriate patch referenced in Microsoft Security Bulletin MS03-021. Based on the contents of the patch, the vulnerable ActiveX control is implemented in the file wmp.dll and the kill bit is not set for the vulnerable control. Under certain circumstances, it may be possible for an attacker to install a vulnerable version of the ActiveX control on a victim's system.

Disable Active scripting and ActiveX controls

Active scripting must be enabled for an attacker to exploit the Windows Media Player 9 Series ActiveX control in the manner discussed in MS03-021. A set of Internet Explorer zone security settings govern the behavior of ActiveX controls based on whether or not a control is signed, marked safe for scripting, or accessible via Active scripting. At a minimum, disable Active scripting and limit the functionality of ActiveX controls in the Internet zone and the zone used by Outlook, Outlook Express, or any other application that uses Internet Explorer or the WebBrowser control to render HTML. Instructions for disabling Active scripting and ActiveX controls can be found in the CERT/CC Malicious Web Scripts FAQ.

Apply the Outlook Email Security Update

Another way to effectively disable Active scripting and ActiveX controls in Outlook is to install the Outlook Email Security Update. The update configures Outlook to open email messages in the Restricted Sites Zone, where Active scripting and ActiveX controls are disabled by default. In addition, the update provides further protection against malicious code that attempts to propagate via Outlook. The Outlook Email Security Update is available for Outlook 98 and Outlook 2000. The functionality of the Outlook Email Security Update is included in Outlook 2002 and Outlook Express 6.

Systems Affected

http://www.microsoft.com/technet/security/bulletin/MS03-021.asp
http://support.microsoft.com/default.aspx?scid=kb;en-us;819639
http://www.ntbugtraq.com/default.asp?pid=36&sid=1&A2=ind0306&L=ntbugtraq&F=P&S=&P=6169
http://www.ntbugtraq.com/default.asp?pid=36&sid=1&A2=ind0307&L=ntbugtraq&F=P&S=&P=1494
http://www.secunia.com/advisories/9114/
http://www.securityfocus.com/bid/8034
http://xforce.iss.net/xforce/xfdb/12440
http://www.securiteam.com/windowsntfocus/5OP0N1FAAO.html
http://support.microsoft.com/support/kb/articles/q240/7/97.asp
http://www.microsoft.com/security/security_bulletins/ms03-021.asp
http://securitytracker.com/alerts/2003/Jun/1007057.html

Credit

This vulnerability was reported by the Microsoft Security Team. MS03-021 credits Jelmer.

This document was written by Art Manion.

Other Information

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