The remote host is missing an update as announced via advisory SSA:2007-109-01.
New x11 and/or freetype and fontconfig packages are available for Slackware 10.1, 10.2, 11.0, and -current to fix security issues in freetype. Freetype was packaged with X11 prior to Slackware version 11.0.
More details about this issue may be found in the Common Vulnerabilities and Exposures (CVE) database: