The remote host is missing an update to dbus announced via advisory USN-799-1.
Details follow:
It was discovered that the D-Bus library did not correctly validate signatures. If a local user sent a specially crafted D-Bus key, they could spoof a valid signature and bypass security policies.
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 6.06 LTS: libdbus-1-2 0.60-6ubuntu8.4
Ubuntu 8.04 LTS: libdbus-1-3 1.1.20-1ubuntu3.3
Ubuntu 8.10: libdbus-1-3 1.2.4-0ubuntu1.1
Ubuntu 9.04: libdbus-1-3 1.2.12-0ubuntu2.1
After a standard system upgrade you need to reboot your computer to effect the necessary changes.