The Adobe Reader control in Adobe Reader and Acrobat 7.0 and 7.0.1 allows remote attackers to determine the existence of files via Javascript containing XML script, aka the "XML External Entity vulnerability."
The Acrobat web control in Adobe Acrobat and Acrobat Reader 7.0 and earlier, when used with Internet Explorer, allows remote attackers to determine the existence of arbitrary files via the LoadFile ActiveX method.
Adobe Acrobat Reader 6.0.3 and 7.0.0 allows remote attackers to cause a denial of service (application crash) via a PDF file that contains a negative Count value in the root page node.