The remote host is missing an update to dbus announced via advisory DSA 2149-1.
Rémi Denis-Courmont discovered that dbus, a message bus application, is not properly limiting the nesting level when examining messages with extensive nested variants. This allows an attacker to crash the dbus system daemon due to a call stack overflow via crafted messages. For the stable distribution (lenny), this problem has been fixed in version 1.2.1-5+lenny2. For the testing distribution (squeeze), this problem has been fixed in version 1.2.24-4. For the unstable distribution (sid), this problem has been fixed in version 1.2.24-4. We recommend that you upgrade your dbus packages.