Firefox before 1.0 and Mozilla before 1.7.5 display the secure site lock icon when a view-source: URL references a secure SSL site while an insecure page is being loaded, which could facilitate phishing attacks.
Firefox before 1.0 and Mozilla before 1.7.5 allows inactive (background) tabs to launch dialog boxes, which can allow remote attackers to spoof the dialog boxes from web sites in other windows and facilitate phishing attacks, aka the "Dialog Box Spoofing Vulnerability."