A remote attacker can read information from a Netscape user's cache via JavaScript.

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.

Buffer overflow in Netscape Communicator via EMBED tags in the pluginspage option.

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".

The byte code verifier component of the Java Virtual Machine (JVM) allows remote execution through malicious web pages.

Java in Netscape 4.5 does not properly restrict applets from connecting to other hosts besides the one from which the applet was loaded, which violates the Java security model and could allow remote attackers to conduct unauthorized activities.

JavaScript in Internet Explorer 3.x and 4.x, and Netscape 2.x, 3.x and 4.x, allows remote attackers to monitor a user's web activities, aka the Bell Labs vulnerability.

The view-source CGI program allows remote attackers to read arbitrary files via a .. (dot dot) attack.