The Expo plugin in Compiz Fusion 0.7.8 allows local users with physical access to drag the screen saver aside and access the locked desktop by using Expo mouse shortcuts, a related issue to CVE-2007-3920.
https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00878.html
https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00860.html
https://exchange.xforce.ibmcloud.com/vulnerabilities/47172
http://www.securityfocus.com/bid/32712
http://secunia.com/advisories/34465