Firefox before 1.0.1 and Mozilla before 1.7.6 allows remote attackers to spoof the SSL "secure site" lock icon via (1) a web site that does not finish loading, which shows the lock of the previous site, (2) a non-HTTP server that uses SSL, which causes the lock to be displayed when the SSL handshake is completed, or (3) a URL that generates an HTTP 204 error, which updates the icon and location information but does not change the display of the original site.