Summary
The remote host is missing an update as announced
via advisory SSA:2003-259-02.
Solution
https://secure1.securityspace.com/smysecure/catid.html?in=SSA:2003-259-02
Insight
Upgraded ProFTPD packages are available for Slackware 8.1, 9.0 and - -current. These fix a security issue where an attacker could gain a root shell by downloading a specially crafted file.