This script is Copyright (C) 2009-2013 Tenable Network Security, Inc.
The remote FreeBSD host is missing a security-related update.
The official ruby site reports :
There is a heap overflow vulnerability in String#ljust, String#center
and String#rjust. This has allowed an attacker to run arbitrary code
in some rare cases.
See also :
Update the affected package.
Risk factor :
Critical / CVSS Base Score : 10.0