Netgear Wireless Cable Modem Gateway – Authentication Bypass / Cross-Site Request Forgery

  • 作者: Sense of Security
    日期: 2011-09-20
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/17874/
  • Sense of Security - Security Advisory - SOS-11-011
    
    Release Date.20-Sep-2011
    Last Update. -
    Vendor Notification Date.22-Mar-2011
    Product. NETGEAR Wireless Cable Modem Gateway
     CG814WG
    Affected versions. Hardware 1.03, 
     Software V3.9.26 R14 verified,
     possibly others
    Severity Rating. High
    Impact.Authentication bypass,
     Cross Site Request Forgery
    Attack Vector. Remote without authentication
    Solution Status. Upgrade to R15 (by contacting NETGEAR)
    CVE reference. Not yet assigned
    
    Details.
    The NETGEAR Wireless Cable Modem Gateway CG814WG is supplied by ISP's 
    as customer premises equipment within Australia and abroad. It is a 
    centrally managed ISP solution whereby each ISP's devices run a 
    customised firmware and configuration changes and updates can be pushed 
    out as required. 
    
    Basic authentication is used as the primary and only authentication 
    mechanism for the administrator interface on the device. The basic 
    authentication can be bypassed by sending a valid POST request to the 
    device without sending any authentication header. The response from the 
    device sends the user to another page that requests basic 
    authentication, however at this point the request has already been 
    processed. 
    
    An example of attacks using the basic authentication bypass may include 
    changing the admin password or enabling the remote admin interface 
    (Internet facing). 
    
    Additionally, due to the lack of CSRF protection in the web application, 
    the bypass attack can be coupled with CSRF to have a victim enable the 
    remote admin interface to the Internet, where an attacker can then use 
    the bypass attack again across the remote admin interface to reset the 
    admin password and access the device. This attack is possible when 
    targeting a victim that is behind the NETGEAR device on the same segment 
    as the web administrator interface whom has browsed to a malicious site 
    containing the CSRF attack. 
    
    NETGEAR was notified of this vulnerability on 22 March 2011, but we 
    never received a response or acknowledgement of the issue or fix. Sense 
    of Security notified local ISP's and it was escalated by a local ISP 
    who worked with NETGEAR to develop and test an update. Sense of Security 
    was never provided an opportunity to validate the fixes in the latest 
    firmware version. Given the severity of the issue it would be prudent 
    for NETGEAR to notify and supply an update to all of its customers. 
    
    Proof of Concept. 
    By embedding the below HTML in a website and having a 
    victim browse to the website the remote management interface to the 
    Internet would be enabled. An attacker could then use one of the 
    hardcoded passwords for the device to access it, or use a basic 
    authentication bypass to change the admin password. Alternatively, the 
    attacker could conduct a CSRF attack that implements two POST requests 
    to have the remote admin interface enabled, and the admin password 
    changed. 
    
    The example here is a basic proof of concept, more complex examples 
    which include JavaScript redirects to mask the basic authentication 
    pop-up would be more stealthy. 
    
    <html>
    <head></head>
    <body onLoad=javascript:document.form.submit()>
    <form action="http://192.168.0.1/goform/RgRemoteManagement"
    method="POST" name="form">
    <input type="hidden" name="NetgearRmEnable" value="0x01">
    <input type="hidden" name="NetgearRmPortNumber" value="1337">
    <input type="hidden" name="NetgearUserLevel" value="1">
    </form>
    </body>
    </html>
    
    Solution.
    Ask your ISP to obtain the latest firmware from NETGEAR and deploy it
    to your device.
    
    Discovered by.
    Sense of Security Labs.
    
    About us.
    Sense of Security is a leading provider of information
    security and risk management solutions. Our team has expert
    skills in assessment and assurance, strategy and architecture,
    and deployment through to ongoing management. We are
    Australia's premier application penetration testing firm and
    trusted IT security advisor to many of the country's largest
    organisations.
    
    Sense of Security Pty Ltd 
    Level 8, 66 King St
    Sydney NSW 2000
    AUSTRALIA
    
    T: +61 (0)2 9290 4444
    F: +61 (0)2 9290 4455
    W: http://www.senseofsecurity.com.au
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    The latest version of this advisory can be found at:
    http://www.senseofsecurity.com.au/advisories/SOS-11-011.pdf 
    
    Other Sense of Security advisories can be found at:
    http://www.senseofsecurity.com.au/research/it-security-advisories.php