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://www.postfix.org/CVE-2011-1720.html http://www.vuxml.org/freebsd/3eb2c100-738b-11e0-89f4-001e90d46635.html

The following packages are affected: postfix postfix-base postfix-current postfix-current-base CVE-2011-1720 The SMTP server in Postfix before 2.5.13, 2.6.x before 2.6.10, 2.7.x before 2.7.4, and 2.8.x before 2.8.3, when certain Cyrus SASL authentication methods are enabled, does not create a new server handle after client authentication fails, which allows remote attackers to cause a denial of service (heap memory corruption and daemon crash) or possibly execute arbitrary code via an invalid AUTH command with one method followed by an AUTH command with a different method.