The remote host is missing an update to the system as announced in the referenced advisory.

Update your system with the appropriate patches or software upgrades. http://unbound.nlnetlabs.nl/downloads/CVE-2011-1922.txt http://www.vuxml.org/freebsd/dc96ac1f-86b1-11e0-9e85-00215af774f0.html

The following package is affected: unbound CVE-2011-1922 daemon/worker.c in Unbound 1.x before 1.4.10, when debugging functionality and the interface-automatic option are enabled, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted DNS request that triggers improper error handling.