http://www.gnucitizen.org/blog/dumping-the-admin-password-of-the-bt-home-hub/

We're back with more security attacks against the BT Home Hub (most
popular wireless DSL router in the UK)!

BT added a new security feature on the latest version [1] of the BT
Home Hub firmware (6.2.6.E at time of writing) which changes the
default admin password from 'admin' to the serial number of the
router. From BT Support and Advice [2] site:

"Firmware 6.2.6.E introduces the following improvements: Change
default Hub Manager access password from 'admin' to your unique Hub
serial number"

Well, it turns out that you can get the serial number of the Home Hub
by simply sending a Multi Directory Access Protocol (MDAP) multicast
request in the network where BT Home Hub is located. Yes, you must
already be part of the LAN where the Home Hub is present, either via
ethernet or via Wi-Fi. However, at GNUCITIZEN, we have demonstrated
[3] trivial ways to predict the WEP encryption key of the Home Hub if
you know what you are doing.

In summary, there are two ways to break into a BT Home Hub Wi-Fi network:

- arp replays injection plus weak IVs cracking. This attack is
typically launched using airodump-ng + aireplay-ng + aircrack-ng (I
highly recommend using Backtrack 2 plus the Alfa USB AWUS036S Wi-Fi
adaptor for this attack)
- Predict the Home Hub's default WEP key by bruteforcing a list of
potential candidates which are derived from the SSID (the SSID can be
obtained by anyone of course)

As promised in CONFidence [4], we're releasing the full details
including PoC scripts:
http://www.gnucitizen.org/blog/dumping-the-admin-password-of-the-bt-home-hub/

In summary, there are currently about 3 million BT Home Hub routers in
the UK whose default WEP key AND admin password can be easily
predicted.


ABOUT GNUCITIZEN

GNUCITIZEN is a Cutting Edge, Ethical Hacker Outfit, Information Think
Tank, which primarily deals with all aspects of the art of hacking.
Our work has been featured in established magazines and information
portals, such as Wired, Eweek, The Register, PC Week, IDG, BBC and
many others. The members of the GNUCITIZEN group are well known and
well established experts in the Information Security, Black Public
Relations (PR) Industries and Hacker Circles with widely recognized
experience in the government and corporate sectors and the open source
community.


REFERENCES

[1] "What is the latest version of BT Home Hub firmware?"
http://snipurl.com/29w9o

[2] "What changes are included in the latest BT Home Hub firmware?"
http://snipurl.com/29oo4

[3] "Default key algorithm in Thomson and BT Home Hub routers"
http://www.gnucitizen.org/blog/default-key-algorithm-in-thomson-and-bt-home-hub-routers/

[4] "Cracking into embedded devices and beyond! - CONFidence, Krakow 2008"
http://www.gnucitizen.org/projects/confidence-2008/Cracking%20into%20embedded%20devices%20-%20CONFidence%202K8.pdf

-- 
Adrian 'pagvac' Pastor | Security Consultant and White Hat Hacker | GNUCITIZEN
gnucitizen.com