Mozilla Firefox before 3.0.10 processes a 3xx HTTP CONNECT response before a successful SSL handshake, which allows man-in-the-middle attackers to execute arbitrary web script, in an https site's context, by modifying this CONNECT response to specify a 302 redirect to an arbitrary https web site.
https://exchange.xforce.ibmcloud.com/vulnerabilities/51203
http://www.securityfocus.com/bid/35412
http://research.microsoft.com/apps/pubs/default.aspx?id=79323