Netscape Communicator 6.2.1 allows remote attackers to cause a denial of service in client browsers via a webpage containing a recursive META refresh tag where the content tag is blank and the URL tag references itself.

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.