Permissions, Privileges, and Access Controls
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access restrictions, which allows remote authenticated users, with "access content" privileges, to read the title of an unpublished node via a q=ctools/autocomplete/node/ value accompanied by the first character of the node's title.
CWE-264 - Permissions Privileges and Access Controls
CWE 264 (permissions, privileges, and access controls) is not a weakness in and of itself, rather it is a category of weaknesses related to the management of permissions, privileges, and other security features used to perform access control. If not addressed, the weaknesses in this category allow attackers to gain privileges for an unintended sphere of control, access sensitive information, and execute arbitrary commands.