The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-06:10.nfs.asc

Upgrade your system to the appropriate stable release or security branch dated after the correction date https://secure1.securityspace.com/smysecure/catid.html?in=FreeBSD-SA-06:10.nfs.asc

The Network File System (NFS) allows a host to export some or all of its filesystems so that other hosts can access them over the network and mount them as if they were on local disks. NFS is built on top of the Sun Remote Procedure Call (RPC) framework. A part of the NFS server code charged with handling incoming RPC messages via TCP had an error which, when the server received a message with a zero-length payload, would cause a NULL pointer dereference which results in a kernel panic. The kernel will only process the RPC messages if a userland nfsd daemon is running.