What are the security issues that arise in the use of the NFS（Network File System)？（)

A.Synchronization of user and group IDs is poor, so it is easy to spoof trusted hosts and user names.

B.The lack of logging in one place or on one machine, and the multiple logs this then requires, can create bottlenecks.

C.The possibility arises for Cleartext passwords to be sniffed on the network if it does not use Secure RP

D.NFS uses a weak authentication scheme and transfers information in encrypted form.