Adobe Reader and Acrobat 7.x before 7.1.4, 8.x before 8.1.7, and 9.x before 9.2 do not properly validate input, which allows attackers to cause a denial of service via unspecified vectors.

Per: http://www.adobe.com/support/security/bulletins/apsb09-15.html

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. These vulnerabilities could cause the application to crash and could potentially allow an attacker to take control of the affected system. This update represents the second quarterly security update for Adobe Reader and Acrobat.

Adobe recommends users of Adobe Reader 9.1.3 and Acrobat 9.1.3 and earlier versions update to Adobe Reader 9.2 and Acrobat 9.2. Adobe recommends users of Acrobat 8.1.6 and earlier versions update to Acrobat 8.1.7, and users of Acrobat 7.1.3 and earlier versions update to Acrobat 7.1.4. For Adobe Reader users who cannot update to Adobe Reader 9.2, Adobe has provided the Adobe Reader 8.1.7 and Adobe Reader 7.1.4 updates. Updates apply to all platforms: Windows, Macintosh and UNIX.
Affected software versions

Adobe Reader 9.1.3 and earlier versions for Windows, Macintosh, and UNIX
Adobe Acrobat 9.1.3 and earlier versions for Windows and Macintosh

Per: http://www.adobe.com/support/security/bulletins/apsb09-15.html
Adobe Reader

Adobe Reader users on Windows can find the appropriate update here: http://www.adobe.com/support/downloads/product.jsp?product=10&platform=Windows.

Adobe Reader users on Macintosh can find the appropriate update here: http://www.adobe.com/support/downloads/product.jsp?product=10&platform=Macintosh.

Adobe Reader users on UNIX can find the appropriate update here: http://www.adobe.com/support/downloads/product.jsp?product=10&platform=Unix.

Acrobat

Acrobat Standard and Pro users on Windows can find the appropriate update here:
http://www.adobe.com/support/downloads/product.jsp?product=1&platform=Windows.

Acrobat Pro Extended users on Windows can find the appropriate update here: http://www.adobe.com/support/downloads/product.jsp?product=158&platform=Windows

Acrobat 3D users on Windows can find the appropriate update here:
http://www.adobe.com/support/downloads/product.jsp?product=112&platform=Windows.

Acrobat Pro users on Macintosh can find the appropriate update here:
http://www.adobe.com/support/downloads/product.jsp?product=1&platform=Macintosh.