Troubleshooting Guide: Fixing Vulnhub Target Machine IP Address Issues

Problem Description

After importing a Vulnhub target machine into VirtualBox and starting it, you may find that running the netdiscover tool on Kali Linux fails to detect the machine's IP address. This is a common issue that many users encounter.

Example output of the failed scan:

└─$ sudo netdiscover -i eth1 
Currently scanning: Starting.   |   Screen View: Unique Hosts              
 0 Captured ARP Req/Rep packets, from 0 hosts.   Total size: 0              
   IP            At MAC Address     Count     Len  MAC Vendor / Hostname      
----------------------------------------------------------------------------

Troubleshooting Steps

1. Restart the Target Machine
   Begin by shutting down the target machine completely and restarting it.

2. Enter GRUB Edit Mode
   As the machine boots, hold down the Shift key to bring up the GRUB menu. Press e to enter edit mode. Locate the line starting with ro and change it to:

   rw single init=/bin/bash

   Additionally, delete any content following this modification until the initrd line. (Note: Simply changing ro without removing subsequent text may prevent successful boot.)

3. Reset the Root Password After making the changes, press Ctrl + X to boot the system. This will start the machine in single-user mode (without requiring a root password). Once logged in, reset the root password using the command:

   

   

4. Modify Network Configuration (Note: This step assumes the target machine is Ubuntu-based. For CentOS-based systems, the configuration file and commands will differ.) After rebooting, check network interfaces using ip a. If no IP address is assigned, edit the network configuration file:

   vi /etc/netplan/00-installer-config.yaml

   Ensure the network interface name in the configuration matches the one displayed by the ip a command.

   

5. Verify IP Address Detection**
   After the reboot, run netdiscover again from your Kali Linux system. The target machine's IP should now be visible:

└─$ sudo netdiscover -i eth1 
Currently scanning: 192.168.60.0/16   |   Screen View: Unique Hosts        
3 Captured ARP Req/Rep packets, from 3 hosts.   Total size: 180            
  IP            At MAC Address     Count     Len  MAC Vendor / Hostname      
----------------------------------------------------------------------------
192.168.56.1    0a:00:27:00:00:11      1      60  Unknown vendor           
192.168.56.100  08:00:27:32:e2:52      1      60  PCS Systemtechnik GmbH   
192.168.56.110  08:00:27:49:41:41      1      60  PCS Systemtechnik GmbH