Integer overflow in Adobe Reader 7 and Acrobat 7 before 7.1.3, Adobe Reader 8 and Acrobat 8 before 8.1.6, and Adobe Reader 9 and Acrobat 9 before 9.1.2 allows attackers to cause a denial of service or possibly execute arbitrary code via a PDF file containing unspecified parameters to the FlateDecode filter, which triggers a heap-based buffer overflow.

More... (http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2009-1856)