Add a scanner aux module for Rails JSON/YAML vuln CVE-2013-0333

modules/auxiliary/scanner/http/rails_json_yaml_scanner.rb

@@ -0,0 +1,101 @@
+##
+# This file is part of the Metasploit Framework and may be subject to
+# redistribution and commercial restrictions. Please see the Metasploit
+# Framework web site for more information on licensing and terms of use.
+#   http://metasploit.com/framework/
+##
+
+require 'msf/core'
+
+class Metasploit3 < Msf::Auxiliary
+
+	include Msf::Exploit::Remote::HttpClient
+	include Msf::Auxiliary::Scanner
+
+	def initialize(info={})
+		super(update_info(info,
+			'Name'        => 'Ruby on Rails JSON Processor YAML Deserialization Scanner',
+			'Description' => %q{
+				This module attempts to identify Ruby on Rails instances vulnerable to
+				an arbitrary object instantiation flaw in the JSON request processor.
+			},
+			'Author'      => [
+						'jjarmoc',	# scanner module
+						'hdm'		# CVE-2013-0156 scanner, basis of this technique.
+						],
+			'License'     => MSF_LICENSE,
+			'References'  =>
+				[
+					['CVE', '2013-0333'],
+				]
+		))
+
+		register_options([
+			OptString.new('URIPATH', [true, "The URI to test", "/"]),
+			OptEnum.new('HTTP_METHOD', [true, 'HTTP Method', 'POST', ['GET', 'POST', 'PUT']]),
+		], self.class)
+	end
+
+	def send_probe(pdata)
+		res = send_request_cgi({
+			'uri'    => datastore['URIPATH'] || "/",
+			'method' => datastore['HTTP_METHOD'],
+			'ctype'  => 'application/json',
+			'data'   => pdata
+		}, 25)
+	end
+
+	def run_host(ip)
+
+		# Straight JSON as a baseline
+		res1 = send_probe(
+			"{ \"#{Rex::Text.rand_text_alpha(rand(8)+1)}\" : \"#{Rex::Text.rand_text_alpha(rand(8)+1)}\" }"
+			)
+
+		unless res1
+			vprint_status("#{rhost}:#{rport} No reply to the initial JSON request")
+			return
+		end
+
+		if res1.code.to_s =~ /^[5]/
+			print_error("#{rhost}:#{rport} The server replied with #{res1.code} for our initial JSON request")
+			print_error("\t\tDouble check URIPATH and HTTP_METHOD")
+			return
+		end
+
+		# Deserialize a hash, this should work if YAML deserializes.
+		res2 = send_probe("--- {}\n".gsub(':', '\u003a'))
+
+		unless res2
+			vprint_status("#{rhost}:#{rport} No reply to the initial YAML probe")
+			return
+		end
+
+		# Deserialize a malformed object, inducing an error.
+		res3 = send_probe("--- !ruby/object:\x00".gsub(':', '\u003a'))
+
+		unless res3
+			vprint_status("#{rhost}:#{rport} No reply to the second YAML probe")
+			return
+		end
+
+		vprint_status("Probe response codes: #{res1.code} / #{res2.code} / #{res3.code}")
+
+		if (res2.code == res1.code) and (res3.code != res2.code) and (res3.code != 200)
+			# If first and second requests are the same, and the third is different but not a 200, we're vulnerable.
+			print_good("#{rhost}:#{rport} is likely vulnerable due to a #{res3.code} reply for invalid YAML")
+			report_vuln({
+				:host	=> rhost,
+				:port	=> rport,
+				:proto  => 'tcp',
+				:name	=> self.name,
+				:info	=> "Module triggered a #{res3.code} reply",
+				:refs   => self.references
+			})
+		else
+			# Otherwise we're not likely vulnerable.
+			vprint_status("#{rhost}:#{rport} is not likely to be vulnerable or URIPATH must be set")
+		end
+	end
+
+end