Hack a DHCP Server

How To Hack a DHCP Server

What is DHCP?
Dynamic Host Configuration Protocol ( DHCP ) is a
network protocol that enables a server to automatically
assign an IP address to a computer from a defined
range of numbers (i.e., a scope) configured for a given
network.
DHCP work on DORA concept.
1. Client makes a UDP Broadcast to the server with a
DHCPDiscover, or Discover packet.
2. DHCP offers to the client. The server sends a
DHCPOffer including other configuration parameters
(DHCP Options) for the client per the servers
configuration file
3. In response to the offer Client requests the server.
The client replies DHCPRequest, unicast to the server,
requesting the offered address.
4.The server sends DHCP Ack acknowledging the
request which is the clients final permission to take the
address as offered. Before sending the ack the server
double checks that the offered address is still available,
that the parameters match the clients request and (if
so) marks the address taken.
Attack on DHCP Server :-
Open the Kali Linux terminal and type the command
root@kali:~#yersinia -G to open the GUI interface of
yersinia.
now click on the Launch Attack option and select the
DHCP option.
now select the Sending DISCOVER packet option for
your attack.and click on the OK.
now it will start the attack on DHCP server , it will send
ton of packets on your DHCP server within second.
With Yersinia , you are able to attack on CDP , DHCP ,
802.1Q , 802.1X ,DTP , HSRP, ISL , STP and VTP
protocols.
Countermeasures or Mitigation :-
You need to be enable DHCP Snooping on the Cisco
Switches:-
DHCP snooping allows the configuration of ports as
trusted or untrusted
Untrusted ports cannot process DHCP replies
Configure DHCP snooping on uplinks to a DHCP
server
Do not configure DHCP snooping on client ports.
Configuring DHCP Snooping

Note :- This Tutorial is for Education Purpose only.

-H4ckz