The remote host is missing an update as announced via advisory SSA:2004-202-01.
New PHP packages are available for Slackware 8.1, 9.0, 9.1, 10.0, and -current to fix security issues (memory_limit handling and a problem in the strip_tags function). Sites using PHP should upgrade.
More details about this issue may be found in the Common Vulnerabilities and Exposures (CVE) database: