Security is an ongoing thing, but old ghosts can reappear. ;D
This was the case with the seven year old security flaw in Mozilla: a frame injection vulnerability. Read about this here: http://software.silicon.com/security/0,39024655,39131016,00.htm . See rectification by DavidR below, the author of this posting agrees with this comment. Point taken generously.
Description:
A seven year old vulnerability has been re-introduced in Mozilla and Firefox, which can be exploited by malicious people to spoof the contents of web sites.