Opera before 10.61 does not properly suppress clicks on download dialogs that became visible after a recent tab change, which allows remote attackers to conduct clickjacking attacks, and consequently execute arbitrary code, via vectors involving (1) closing a tab or (2) hiding a tab, a related issue to CVE-2005-2407.
secunia.com/secunia_research/2010-110/
www.opera.com/docs/changelogs/mac/1061/
www.opera.com/docs/changelogs/unix/1061/
www.opera.com/docs/changelogs/windows/1061/
www.opera.com/support/kb/view/967/
www.securityfocus.com/archive/1/513040/100/0/threaded
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12084