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://proxytunnel.sourceforge.net/news.html http://www.gentoo.org/security/en/glsa/glsa-200411-07.xml http://www.vuxml.org/freebsd/50744596-368f-11d9-a9e7-0001020eed82.html

The following package is affected: proxytunnel CVE-2004-0992 Format string vulnerability in the -a option (daemon mode) in Proxytunnel before 1.2.3 allows remote attackers to execute arbitrary code via format string specifiers in an invalid proxy answer.