Mozilla Firefox might allow remote attackers to conduct spoofing and phishing attacks by writing to an about:blank tab and overlaying the location bar.
https://exchange.xforce.ibmcloud.com/vulnerabilities/32580
http://www.securityfocus.com/bid/22601
http://www.securityfocus.com/archive/1/460617/100/0/threaded
http://www.securityfocus.com/archive/1/460412/100/0/threaded
http://www.securityfocus.com/archive/1/460369/100/0/threaded
http://securityreason.com/securityalert/2264