Buffer overflow in the sun.awt.windows.WDefaultFontCharset Java class implementation in Netscape 4.0 allows remote attackers to execute arbitrary code via an applet that calls the WDefaultFontCharset constructor with a long string and invokes the canConvert method.

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 4.0 through 4.79 allows remote attackers to bypass JVM security and execute arbitrary Java code via an applet that loads user-supplied Java classes.

The POP3 mail client in Mozilla 1.0 and earlier, and Netscape Communicator 4.7 and earlier, allows remote attackers to cause a denial of service (no new mail) via a mail message containing a dot (.) at a newline, which is interpreted as the end of the message.

Netscape Communicator 4.x allows attackers to use a link to steal a user's preferences, including potentially sensitive information such as URL history, e-mail address, and possibly the e-mail password, by redefining the userpref() function and accessing the prefs.js file, which is stored in a directory with a predictable name.

Mozilla 0.9.6 and earlier and Netscape 6.2 and earlier allows remote attackers to steal cookies from another domain via a link with a hex-encoded null character (%00) followed by the target domain.