The remote host is missing an update as announced via advisory SSA:2004-266-01.

https://secure1.securityspace.com/smysecure/catid.html?in=SSA:2004-266-01

New CUPS packages are available for Slackware 9.1, 10.0, and -current to fix a denial of service issue where a malformed packet can crash the CUPS server. More details about this issue may be found in the Common Vulnerabilities and Exposures (CVE) database: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-0558