Buffer overflow in Netscape Navigator/Communicator 4.7 for Windows 95 and Windows 98 allows remote attackers to cause a denial of service, and possibly execute arbitrary commands, via a long argument after the ? character in a URL that references an .asp, .cgi, .html, or .pl file.
Netscape Communicator 4.7 and earlier allows remote attackers to cause a denial of service, and possibly execute arbitrary commands, via a long certificate key.
Netscape Communicator 4.04 through 4.7 (and possibly other versions) in various UNIX operating systems converts the 0x8b character to a "<" sign, and the 0x9b character to a ">" sign, which could allow remote attackers to attack other clients via cross-site scripting (CSS) in CGI programs that do not filter these characters.
Netscape Communicator 4.x with Javascript enabled does not warn a user of cookie settings, even if they have selected the option to "Only accept cookies originating from the same server as the page being viewed".
When Javascript is embedded within the TITLE tag, Netscape Communicator allows a remote attacker to use the "about" protocol to gain access to browser information.