Netscape Messaging Server 3.54, 3.55, and 3.6 allows a remote attacker to cause a denial of service (memory exhaustion) via a series of long RCPT TO commands.
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.
Default configuration of the search engine in Netscape Enterprise Server 3.5.1, and possibly other versions, allows remote attackers to read the source of JHTML files by specifying a search command using the HTML-tocrec-demo1.pat pattern file.
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.