CVE 2010-1384
Apple Safari before 5.0 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1 on Mac OS X 10.4, does not provide a warning about a (1) http or (2) https URL that contains a username and password, which makes it easier for remote attackers to conduct phishing attacks via a crafted URL.
See the 
CVE page on Mitre.org
for more details.
