Adobe has identified a critical security vulnerability in the recent versions of both Acrobat and Reader. It is a buffer overflow issue in versions 7,8, and 9 of Acrobat, Acrobat Pro, and Acrobat Pro Extended.
Versions 7,8, 9, and even the FREE version of Adobe Reader can cause crashing, and can also be exploited to take control of a user’s system.
The exploits, according to Infinite Loop, are already in the wild.
As a Mac user the best thing you can do to prevent this issue from affecting you is to open a PDF file, open the “Get info” of the file, then select “Open Width..” and the Change All Button…then select “Display PDF in browser using Adobe Reader (or whatever version of the program you’re currently using.
If you don’t use Adobe Reader you should be fine.