This script is Copyright (C) 2005-2013 Tenable Network Security, Inc.
The remote FreeBSD host is missing a security-related update.
The squid patches page notes :
Malicious users may spoof DNS lookups if the DNS client UDP port
(random, assigned by OS as startup) is unfiltered and your network is
not protected from IP spoofing.
See also :
Update the affected package.
Risk factor :
Medium / CVSS Base Score : 6.4