The remote host is missing an update to netscape announced via advisory DSA 051-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20051-1

Florian Wesch has discovered a problem (reported to bugtraq) with the way how Netscape handles comments in GIF files. The Netscape browser does not escape the GIF file comment in the image information page. This allows javascript execution in the 'about:' protocol and can for example be used to upload the History (about:global) to a webserver, thus leaking private information. This problem has been fixed upstream in Netscape 4.77. Since we haven't received sourcecode for these packages they are not part of the Debian GNU/Linux distribution but are packaged up as `.deb' files for a convenient installation. We recommend that you upgrade your Netscape packages immediately and