The remote host is missing an update as announced via advisory SSA:2008-128-01.

https://secure1.securityspace.com/smysecure/catid.html?in=SSA:2008-128-01

New php packages are available for Slackware 10.2, 11.0, 12.0, 12.1, and -current to fix security issues. Note that PHP5 is not the default PHP for Slackware 10.2 or 11.0 (those use PHP4), so if your PHP code is not ready for PHP5, don't upgrade until it is or you'll (by definition) run into problems. More details about one of the issues may be found in the Common Vulnerabilities and Exposures (CVE) database: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-0599