probers/udisks-dm-export.c in udisks before 1.0.1 exports UDISKS_DM_TARGETS_PARAMS information to udev even for a crypt UDISKS_DM_TARGETS_TYPE, which allows local users to discover encryption keys by (1) running a certain udevadm command or (2) reading a certain file under /dev/.udev/db/.
https://launchpad.net/bugs/556651
https://bugzilla.redhat.com/show_bug.cgi?id=580005
https://bugzilla.novell.com/show_bug.cgi?id=594261
https://bugs.freedesktop.org/show_bug.cgi?id=27494
http://www.securityfocus.com/bid/39265
http://secunia.com/advisories/39332
http://lists.fedoraproject.org/pipermail/package-announce/2010-April/039060.html
http://cgit.freedesktop.org/udisks/commit/?id=0fcc7cb3b66f23fac53ae08647aa0007a2bd56c4