Netgear DG632 Router Remote Denial of Service Vulnerability

Product Name: Netgear DG632 Router Vendor: http://www.netgear.com Date: 15 June, 2009 Author: tom@tomneaves.co.uk < tom@tomneaves.co.uk > 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 # sebug.net