Microsoft Windows Media Player 7, Build 1956, Security Patch: ASX Buffer Overrun and WMS Script Execution Vulnerabil 11-22-00

The ASX Buffer Overrun vulnerability: Windows Media Player supports the use of Active Stream Redirector (.ASX) files to enable users to play streaming media that resides on intranet or Internet sites. However, the code that parses .ASX files has an unchecked buffer, and this could potentially enable a malicious user to run code of his choice on the machine of another user. The malicious user could either send an affected file to another user and entice her to run or preview it, or he could host such a file on a web site and cause it to launch automatically whenever a user visited the site. The code could take any action on the machine that the legitimate user herself could take.The WMS Script Execution vulnerability: Windows Media Player 7 introduced a feature called skins, that allows customization of the look and feel of Windows Media Player. However, a custom skin (.WMS) file could potentially include script, which would execute if Windows Media Player was run and that skin was selected. A malicious user could either send a customized skin containing script to another user and try to entice her into using it, or he could host such a file on a web site and cause it to launch automatically whenever a user visited the site. Because the code would reside on the user’s local machine, it would be able to execute ActiveX controls, including ones not marked safe for scripting. This would enable the code to take any action that can be accomplished via an ActiveX control.This update can only be installed on Windows Media Player 7, Build 1956. You can check the build number of your Windows Media Player by selecting Help | About Windows Media Player. If the number displayed is less than 7.00.00.1956, please download and install the latest version of Windows Media Player from the Microsoft website (http://www.microsoft.com/windows/windowsmedia/download) prior to installing this update. This patch is for the Windows 98/ME/2000 operating system only. Since Windows Media Player version 7 does not run on Windows 95 and NT, Windows 95 and NT users should download and apply the patch for Windows Media Player version 6.4 if applicable.