Linux Kernel 2.6.x Cryptoloop Information Disclosure Vulnerability

                                                source: http://www.securityfocus.com/bid/13775/info

Both cryptoloop and dm-crypt are reported prone to an information disclosure vulnerability. Reports indicate that certain watermarked files may be detected on a filesystem that is encrypted using the affected loop device encryption schemes.

It should be noted that a successful attack would reveal the presence of a watermarked file but not the file contents. 

http://www.exploit-db.com/sploits/25707.tar.bz2