Re: [Full-disclosure] Netgear DG632 Router Remote DoS Vulnerability

["Tom Neaves" <tom@xxxxxxxxxxxxxxx>]

Hi.

I'm not quite sure of your question...

The DoS can be carried out remotely, however one mitigating factor (which makes 
it a low risk as opposed to sirens and alarms...) is that its turned off by 
default - you have to explicitly enable it under "Remote Management" on the 
device if you want to access it/carry out the DoS over the Internet.  However, 
it is worth noting that anyone on your LAN can *remotely* carry out this attack 
regardless of this management feature being on/off.

I hope this clarifies it for you.

Tom
  ----- Original Message ----- 
  From: Alaa El yazghi 
  To: Tom Neaves 
  Cc: bugtraq@xxxxxxxxxxxxxxxxx ; full-disclosure@xxxxxxxxxxxxxxxxx 
  Sent: Monday, June 15, 2009 10:45 PM
  Subject: Re: Netgear DG632 Router Remote DoS Vulnerability


  How can it be carried out remotely if it bugs localy?


  2009/6/15 Tom Neaves <tom@xxxxxxxxxxxxxxx>

    Product Name: Netgear DG632 Router
    Vendor: http://www.netgear.com
    Date: 15 June, 2009
    Author: tom@xxxxxxxxxxxxxxx <tom@xxxxxxxxxxxxxxx>
    Original URL: http://www.tomneaves.co.uk/Netgear_DG632_Remote_DoS.txt
    Discovered: 18 November, 2006
    Disclosed: 15 June, 2009

    I. DESCRIPTION

    The Netgear DG632 router has a web interface which runs on port 80.  This
    allows an admin to login and administer the device's settings.  However,
    a Denial of Service (DoS) vulnerability exists that causes the web interface
    to crash and stop responding to further requests.

    II. DETAILS

    Within the "/cgi-bin/" directory of the administrative web interface exists 
a
    file called "firmwarecfg".  This file is used for firmware upgrades.  A 
HTTP POST
    request for this file causes the web server to hang.  The web server will 
stop
    responding to requests and the administrative interface will become 
inaccessible
    until the router is physically restarted.

    While the router will still continue to function at the network level, i.e. 
it will
    still respond to ICMP echo requests and issue leases via DHCP, an 
administrator will
    no longer be able to interact with the administrative web interface.

    This attack can be carried out internally within the network, or over the 
Internet
    if the administrator has enabled the "Remote Management" feature on the 
router.

    Affected Versions: Firmware V3.4.0_ap (others unknown)

    III. VENDOR RESPONSE

    12 June, 2009 - Contacted vendor.
    15 June, 2009 - Vendor responded.  Stated the DG632 is an end of life 
product and is no
    longer supported in a production and development sense, as such, there will 
be no further
    firmware releases to resolve this issue.

    IV. CREDIT

    Discovered by Tom Neaves 


_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/