The history-clearing feature in Safari in Apple iOS before 7 does not clear the back/forward history of an open tab, which allows physically proximate attackers to obtain sensitive information by leveraging an unattended workstation.
Apple Security Advisory 2014-10-16-1 - OS X Yosemite v10.10 is now available and addresses 802.1X, AFP file server, Apache, App Sandbox, and various other vulnerabilities.