Message-ID: <60524EB9-868F-11D8-9DAC-000A95B0F6B4@remote-exploit.org>
Date: Mon, 5 Apr 2004 01:25:36 +0200
From: Max Moser <mmo@...ote-exploit.org>
To: bugtraq@...urityfocus.com
Subject: Automated wireless client penetration tool "hotspotter" released.


I would like to announce the availability of a proof of concept tool 
release. Hotspotter automates a method of penetration against wireless 
clients, independent of the encryption mechanism used. Get it at 
http://www.remote-exploit.org now.

Feel free to provide feedback, below you will find some further 
information copied from the README file.

Greetings

Max Moser


Background:
-----------
During a wireless assessment for a customer some time ago, I discovered 
a
strange characteristic of the Microsoft Windows XP wireless client. It 
was
possible to bring the client from a secure EAP/TLS network to an 
insecure one
without any warnings from the operating system.  I discovered this was 
due to
the configuration of multiple wireless profiles. One profile was 
established
for the EAP/TLS network, and a second for the "ANY" network, using an 
empty
network name (SSID).

To evaluate this configuration, I established my own access point using 
the
same SSID as the EAP/TLS network, without the privacy bit set (no 
encryption).
Due to the configuration of the Windows XP client, I was able to force 
the
client to switch to my network with a single deauthenticate frame; at 
which
point the client reconnected to my "rogue" access point. The victim 
station did
not receive a warning from the operating system to indicate they left 
their
production network, only a small indicator for temporary wireless 
signal.

With this attack, I was able to force a client to leave their secure 
wireless
network and reconnect to my rogue network, albeit at a loss of network
connectivity.  This allowed me to evaluate the host-based security of 
the
victim host, without the protection of the EAP/TLS network.

This behaviour seems to be fixed in Windows XP Service Pack 1.  I was 
unable to
locate any documentation in the Microsoft Knowledge Base that indicated 
the
resolution of this flaw, but there is a remaining vulnerability that 
can also
be exploited based configured wireless profiles.

A Windows XP client will probe for all the preferred network names 
listed in
the wireless client configuration during startup, powersave-wakeup and 
when the
driver reports signal loss for the current network name.  Many coporate
wireless users configure Windows XP with a business profile (secure 
network
profile) and several other network names including commercial hotspots 
and home
networks (insecure network profiles).  Due to this configuration, it is
possible to force a client to disclose the list of configured profiles, 
and
then establish a connection to a rogue network using one of the 
preferred
network names.  Depending on the configuration of the wireless client, 
the
client will display a bubble message indicating it has joined a 
different
wireless network name.

Once the associates to the rogue network, it is possible to interact 
with the
client directly.  This may include port scanning the victim, exploiting
Windows-based vulnerabilities or simulating an otherwise "real" network 
using
faked services and intercepted DNS queries.

Note that the Apple OS X client exhibits similar behaviour, although it 
has not
been thoroughly tested at this time.


Automated penetration using Hotspotter
--------------------------------------
Hotspotter was written to exploit this weakness in the Windows XP Wlan 
client
system.  Hotspotter passively monitors the network for probe request 
frames to
identify the preferred networks of Windows XP clients, and will compare 
it to a
supplied list of common hotspot network names.  If the probed network 
name
matches a common hotspot name, Hotspotter will act as an access point 
to allow
the client to authenticate and associate.  Once associated, Hotspotter 
can be
configured to run a command, possibly a script to kick off a DHCP 
daemon and
other scanning against the new victim.

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