The remote host is missing an update to several announced via advisory DSA 773-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20773-1

This advisory adds security support for the stable amd64 distribution. It covers all security updates since the release of sarge, which were missing updated packages for the not yet official amd64 port. Future security advisories will include updates for this port as well.