Opera before 11.01 does not properly restrict the use of opera: URLs, which makes it easier for remote attackers to conduct clickjacking attacks via a crafted web site.
osvdb.org/70729
secunia.com/advisories/43023
www.opera.com/docs/changelogs/mac/1101/
www.opera.com/docs/changelogs/unix/1101/
www.opera.com/docs/changelogs/windows/1101/
www.opera.com/support/kb/view/983/
www.securityfocus.com/bid/46036
www.vupen.com/english/advisories/2011/0231
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11641