There is a security vulnerability in Netscape Communicator 4.6 Win95, 4.07 Linux (probably all 4.x versions) in the way
The problem is that it allows access to documents included in the parent document via
ILAYER SRC="view-source:wysiwyg://1/" using find(). That allows reading the whole parsed document.
Browsing local directories
Reading user's cache
Reading parsed HTML files
Reading Netscape's configuration ("about:config") including user's email address, mail servers and password.
This vulnerability may be exploited by using HTML email message.
This demonstration tries to find your email address, it may take some time.
Written by Georgi Guninski