How to find hidden RPC Service vulnerabilities

Issue

• Hidden RPC services error while scanning for threats.

Hidden RPC Services
QID: 11 CVSS Base: 5 [1]
Category: RPC CVSS Temporal: 3.6
CVE ID: -
Vendor Reference: -
Bugtraq ID: -
Service Modified: 01/01/1999
User Modified: -
Edited: No
PCI Vuln: Yes
THREAT:
The Portmapper/Rpcbind listens on port 111 and stores an updated list of registered RPC services running on the server (RPC name, version and
port number). It acts as a "gateway" for clients wanting to connect to any RPC daemon.
When the portmapper/rpcbind is removed or firewalled, standard RPC client programs fail to obtain the portmapper list. However, by sending
carefully crafted packets, it's possible to determine which RPC programs are listening on which port. This technique is known as direct RPC
scanning. It's used to bypass portmapper/rpcbind in order to find RPC programs running on a port (TCP or UDP ports). On Linux servers, RPC
services are typically listening on privileged ports (below 1024), whereas on Solaris, RPC services are on temporary ports (starting with port 32700).
IMPACT:
Scan Results page 32
Unauthorized users can build a list of RPC services running on the host. If they discover vulnerable RPC services on the host, they then can exploit
them.
SOLUTION:
Firewalling the portmapper port or removing the portmapper service is not sufficient to prevent unauthorized users from accessing the RPC
daemons. You should remove all RPC services that are not strictly required on this host.
COMPLIANCE:
Not Applicable
EXPLOITABILITY:
There is no exploitability information for this vulnerability.
ASSOCIATED MALWARE:
There is no malware information for this vulnerability.
RESULTS:
Name Program Version Protocol Port
portmap/rpcbind 100000 2-4 tcp 111
portmap/rpcbind 100000 2-4 udp 672

• Need your assistance to disable/remove the rpc services on all our Linux servers and want to know what is the impact of this.