There are different popular ports used for different applications, protocols, etc. The port number 111 is a less known port number that can be used in TCP and UDP protocols. The port 111 is named as sunrpc which means SUN Remote Procedure Call . Even this port is not well known it is a well-defined port number as numbered under 1024. This port is used as portmapper to provides directories and mapping for services and their related ports.
Port 111 and Port 135 Relation
Unix/Linux and Windows are two popular operating systems. These operating systems provide remote process calls by using different protocols and port numbers. The Unix/Linux use port 111 as RPC and services catalog where Windows operating systems use DCOM for port 135.
Is Port 111 Secure?
Port 111 is generally called an unsecured or a security vulnerability as it provides direct and easy access to the RPC services. Port 111 is used in Unix, Linux, and related operating systems to list ports and related RPC services where an attacker can bet detailed information to abuse these services and ports. Also the remote IP address is provided as parameter to the rpcbind.
rpcbind -p 192.168.1.10100001 2 udp 111 portmapper
100000 3 udp 111 portmapper
100005 3 udp 1048 mountd
100022 1 tcp 1047 nlockmgr
100021 4 udp 1047 nlockmgr
100026 1 tcp 1039 status
100029 1 udp 1039 status
100003 2 tcp 2049 nfs
100003 3 tcp 2049 nfsList Services by Connecting Port 111 with rpcbind Command
The Linux and Unix operating systems provide the command rpcbind which connects to the remote system port 111 to list provided services. The option -p is used to list programs and protocols and