iBooks Commerce in Apple OS X before 10.9.4 places Apple ID credentials in the iBooks log, which allows local users to obtain sensitive information by reading this file.
http://www.securitytracker.com/id/1030505
http://support.apple.com/kb/HT6296
http://secunia.com/advisories/59475
http://archives.neohapsis.com/archives/bugtraq/2014-06/0172.html