Microsoft's addresses a flaw with Embedded OpenType fonts that can be attacked through any program that can render the fonts, including Internet Explorer, PowerPoint or Word. A successful attack could hand over complete control of a vulnerable system, according to the bulletin, but only Windows 2000 is vulnerable.
Other versions of Windows "contain the vulnerable code but do not use this code in a way that may expose the vulnerability," according to the bulletin. If you have a Windows 2000 system you'll get this fix via Windows Update.
On the other hand, all Windows, Macintosh and Unix systems with Adobe Reader 9.2 or Acrobat 9.2 will need a program update to version 9.3 to close an that has been targeted with poisoned .pdf files. Acrobat versions 8.1.7 and earlier will likewise require an upgrade to version 8.2. Heading to Help | Check for Updates will get you the update, or download the . For more details see .