Adobe Document Server for Reader Extensions 6.0 includes a user's session (jsession) ID in the HTTP Referer header, which allows remote attackers to gain access to PDF files that are being processed within that session.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25773
http://www.vupen.com/english/advisories/2006/1342
http://www.securityfocus.com/bid/17500
http://www.securityfocus.com/archive/1/430869/100/0/threaded
http://www.adobe.com/support/techdocs/331915.html
http://www.adobe.com/support/techdocs/322699.html