Adobe announced in a security bulletin yesterday that, "Critical vulnerabilities have been identified in Adobe Reader 9.1.3 and Acrobat 9.1.3, Adobe Reader 8.1.6 and Acrobat 8.1.6 for Windows, Macintosh and UNIX, and Adobe Reader 7.1.3 and Acrobat 7.1.3 for Windows and Macintosh." The vulnerabilities in question can cause the programs to crash, giving a potential attacker the ability to take control of the user's system.