News

Flaw Lets Attackers Run Code on Windows XP

• By Scott Bekker
• December 19, 2002

Microsoft alerted users Wednesday night to a critical flaw arising from an unchecked buffer in the Windows XP Shell that could be used to run code of an attacker's choice. The flaw occurs when opening or even hovering over malicious audio files.

Among other functions, the Windows Shell provides the means to start applications. The process the Windows Shell uses to extract custom attribute information from audio files contains an unchecked buffer. A malicious user can exploit the vulnerability with a buffer overrun attack to either cause the Windows Shell to fail or run code in the security context of the user.

To exploit this vulnerability an attacker must have the social engineering skills to entice a user to open or hover over a maliciously created MP3 or Windows Media Audio file from a Web site, network share or HTML e-mail.

"If a user were to hover his or her mouse pointer over the icon for the file (either on a Web page or on the local disk), or open the shared folder where the file was stored, the vulnerable code would be invoked. An HTML e-mail could cause the vulnerable code to be invoked when a user opened or previewed the e-mail," Microsoft's bulletin warns.

The security bulletin, MS02-072, is the 19th of the year affecting Windows XP, and the 21st Windows XP security bulletin since the product was introduced last year.

The bulletin may be found at:
www.microsoft.com/technet/security/bulletin/MS02-072.asp.

On Thursday, the CERT Coordination Center buttressed Microsoft's bulletin with a warning of its own about the flaw. The CERT advisory is available at www.cert.org/advisories/CA-2002-37.html.