The auto-complete functionality in the Chaos Tool Suite (aka CTools) module 6.x before 6.x-1.4 for Drupal does not follow access restrictions, which allows remote authenticated users, with "access content" privileges, to read the title of an unpublished node via a q=ctools/autocomplete/node/ value accompanied by the first character of the node's title.
https://exchange.xforce.ibmcloud.com/vulnerabilities/58724
http://www.securityfocus.com/bid/40285
http://www.madirish.net/?article=458
http://secunia.com/advisories/39884