The downloads manager in Opera before 11.01 on Windows does not properly determine the pathname of the filesystem-viewing application, which allows user-assisted remote attackers to execute arbitrary code via a crafted web site that hosts an executable file.
jvn.jp/en/jp/JVN33880169/index.html
jvndb.jvn.jp/ja/contents/2011/JVNDB-2011-000010.html
osvdb.org/70726
secunia.com/advisories/43023
www.opera.com/docs/changelogs/windows/1101/
www.opera.com/support/kb/view/985/
www.vupen.com/english/advisories/2011/0231
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12369