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.gentoo.org/security/en/glsa/glsa-200503-12.xml http://www.vuxml.org/freebsd/5ebfe901-a3cb-11d9-b248-000854d03344.html

The following package is affected: hashcash CVE-2005-0687 Format string vulnerability in Hashcash 1.16 allows remote attackers to cause a denial of service (memory consumption) and possibly execute arbitrary code via format string specifiers in a reply address, which is not properly handled when printing the header.