The Shibboleth authentication module 5.x before 5.x-3.4 and 6.x before 6.x-3.2, a module for Drupal, does not properly remove statically granted privileges after a logout or other session change, which allows physically proximate attackers to gain privileges by using an unattended web browser.
https://exchange.xforce.ibmcloud.com/vulnerabilities/53779
http://www.vupen.com/english/advisories/2009/2919
http://www.securityfocus.com/bid/36684