This link, among others, shows new Browser Security Bug has been found. Whether this would happen in real life. it is safer to update browsers.
Appears IE6 cannot be changed. Maybe others could concur or otherwise.
Chrome was updated in February.
Firefox will be updated Nov 25th
Internet Explorer no information as to update.
Link shows how to update Firefox.
Internet Explorer Tools/Internet Options/advanced and untick USE SSL2.0, Use SSL 3.0, Use TSL 1.0