Cisco Secure Desktop (CSD) before 3.1.1.45 allows local users to escape out of the secure desktop environment by using certain applications that switch to the default desktop, aka "System Policy Evasion".
https://exchange.xforce.ibmcloud.com/vulnerabilities/30130
http://www.vupen.com/english/advisories/2006/4409
http://www.securityfocus.com/bid/20964
http://www.cisco.com/warp/public/707/cisco-sa-20061108-csd.shtml