[原文]The portmapper may act as a proxy and redirect service requests from an attacker, making the request appear to come from the local host, possibly bypassing authentication that would otherwise have taken place. For example, NFS file systems could be mounted through the portmapper despite export restrictions.
NFS portmapper localhost Mount Request Restricted Host Access
Remote / Network Access
Loss of Integrity
Currently, there are no known upgrades or patches to correct this vulnerability. It is possible to temporarily work around the flaw by implementing the following workaround: restrict access to the portmapper services, as well as the mount and umount binaries.