CEH v13 312-50v13 Passing Score

Example Usage enip-info:

- nmap --script enip-info -sU -p 44818

This NSE script is used to send a EtherNet/IP packet to a remote device that has TCP 44818 open. The script will send a Request Identity Packet and once a response is received, it validates that it was a proper response to the command that was sent, and then will parse out the data. Information that is parsed includes Device Type, Vendor ID, Product name, Serial Number, Product code, Revision Number, status, state, as well as the Device IP.

This script was written based of information collected by using the the Wireshark dissector for CIP, and EtherNet/IP, The original information was collected by running a modified version of the ethernetip.py script

We have various articles already in our documentation for setting up SNMPv2 trap handling in Opsview, but SNMPv3 traps are a whole new ballgame. They can be quite confusing and complicated to set up the first time you go through the process, but when you understand what is going on, everything should make more sense.

SNMP has gone through several revisions to improve performance and security (version 1, 2c and 3). By default, it is a UDP port based protocol where communication is based on a ‘fire and forget’ methodology in which network packets are sent to another device, but there is no check for receipt of that packet (versus TCP port when a network packet must be acknowledged by the other end of the communication link). 

There are two modes of operation with SNMP – get requests (or polling) where one device requests information from an SNMP enabled device on a regular basis (normally using UDP port 161), and traps where the SNMP enabled device sends a message to another device when an event occurs (normally using UDP port 162). The latter includes instances such as someone logging on, the device powering up or down, or a wide variety of other problems that would need this type of investigation.

This blog covers SNMPv3 traps, as polling and version 2c traps are covered elsewhere in our documentation.

SNMP traps

Since SNMP is primarily a UDP port based system, traps may be ‘lost’ when sending between devices; the sending device does not wait to see if the receiver got the trap. This means if the configuration on the sending device is wrong (using the wrong receiver IP address or port) or the receiver isn’t listening for traps or rejecting them out of hand due to misconfiguration, the sender will never know.

The SNMP v2c specification introduced the idea of splitting traps into two types; the original ‘hope it gets there’ trap and the newer ‘INFORM’ traps. Upon receipt of an INFORM, the receiver must send an acknowledgement back. If the sender doesn’t get the acknowledgement back, then it knows there is an existing problem and can log it for sysadmins to find when they interrogate the device.

To prevent networks from sniffing attacks, organizations and individual users should keep away from applications using insecure protocols, like basic HTTP authentication, File Transfer Protocol (FTP), and Telnet. Instead, secure protocols such as HTTPS, Secure File Transfer Protocol (SFTP), and Secure Shell (SSH) should be preferred. In case there is a necessity for using any insecure protocol in any application, all the data transmission should be encrypted. If required, VPN (Virtual Private Networks) can be used to provide secure access to users.

NOTE: I want to note that the wording "best option" is valid only for the EC-Council's exam since the other options will not help against sniffing or will only help from some specific attack vectors.

The sniffing attack surface is huge. To protect against it, you will need to implement a complex of measures at all levels of abstraction and apply controls at the physical, administrative, and technical levels. However, encryption is indeed the best option of all, even if your data is intercepted - an attacker cannot understand it.

In CEH v13 Module 11: Hacking Wireless Networks, wireless standards and their transmission ranges are discussed.

Actual Range Specs:

802.11a: Operates at 5 GHz, range up to ~75 ft indoors, much less than 150 ft due to poor wall penetration.

802.11b/g: Operate at 2.4 GHz, typically 150–300 ft indoors.

802.16 (WiMax): Wireless MAN technology with range up to 30 miles — correct for point-to-point outdoor line of sight.

Conclusion:

802.11a listed as 150–150 ft is incorrect.

Realistic effective range is up to 75 ft indoors, depending on obstructions and interference.

This overestimation makes Option D the wrong one.