Buffer overflow in the HTML parser for Netscape 4.75 and earlier allows remote attackers to execute arbitrary commands via a long password value in a form field.
Netscape Communicator and Navigator 4.04 through 4.74 allows remote attackers to read arbitrary files by using a Java applet to open a connection to a URL using the "file", "http", "https", and "ftp" protocols, as demonstrated by Brown Orifice.
Netscape Communicator does not properly prevent a ServerSocket object from being created by untrusted entities, which allows remote attackers to create a server on the victim's system via a malicious applet, as demonstrated by Brown Orifice.
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.
A configuration in a web browser such as Internet Explorer or Netscape Navigator allows execution of active content such as ActiveX, Java, Javascript, etc.