Adobe Reader and Acrobat - Critical Security Updates
These updates should be applied promptly, as there have been PDF based attacks in the wild involving JavaScript vulnerabilities.
http://www.adobe.com/support/security/bulletins/apsb09-04.html
QUOTE: Critical vulnerabilities have been identified in Adobe Reader 9 and Acrobat 9 and earlier versions. These vulnerabilities would cause the application to crash and could potentially allow an attacker to take control of the affected system. There are reports that one of these issues is being exploited (CVE-2009-0658).
Adobe recommends users of Adobe Reader and Acrobat 9 update to Adobe Reader 9.1 and Acrobat 9.1. Adobe recommends users of Acrobat 8 update to Acrobat 8.1.4, and users of Acrobat 7 update to Acrobat 7.1.1. For Adobe Reader users who can’t update to Adobe Reader 9.1, Adobe has provided the Adobe Reader 8.1.4 and Adobe Reader 7.1.1 updates.
These updates resolve the issue from Security Advisory APSA09-01 and Security Bulletin APSB09-03. Users who have previously updated to Adobe Reader 9.1 and Acrobat 9.1 for Windows and Macintosh need not take any action. As of March 24, Adobe has also made available the Adobe Reader 9.1 and Adobe Reader 8.1.4 updates for Unix