Firefox and Mozilla allow remote attackers to cause a denial of service (application crash from memory consumption), as demonstrated using Javascript code that continuously creates nested arrays and then sorts the newly created arrays.
Mozilla Firefox before 1.0 truncates long filenames in the file download dialog box, which makes it easier for remote attackers to trick users into downloading files with dangerous extensions.
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."
Firefox before 1.0 and Mozilla before 1.7.5 allow inactive (background) tabs to focus on input being entered in the active tab, as originally reported using form fields, which allows remote attackers to steal sensitive data that is intended for other sites, which could facilitate phishing attacks.
Netscape Navigator 7.0.2 and Mozilla allows remote attackers to access cookie information in a different domain via an HTTP request for a domain with an extra . (dot) at the end.