The Private Browsing feature in CFNetwork in Apple Mac OS X before 10.8.4 does not prevent storage of permanent cookies upon exit from Safari, which might allow physically proximate attackers to bypass cookie-based authentication by leveraging an unattended workstation.
The Printing component in Apple Mac OS X 10.5.2 might save authentication credentials to disk when starting a job on an authenticated print queue, which might allow local users to obtain the credentials.