A newly released vulnerability in MS PowerPoint versions 2000 through 2004 for Mac and PC could allow a maliciously crafted PowerPoint file to compromise a user's system and run arbitrary code with permissions of the user. This was reported as a 0-day and is presently (as of April 02, 2009) unpatched. The Microsoft security bulletin can be found at the following link:
Secunia also has a brief summary of the vulnerability here:
The only workaround so far is the standard "don't open untrusted documents".
Posted by Brett Davis on April 03, 2009, in Handlers Log.