Tuesday, October 09, 2007

Eircom Wireless Security

If you are an Eircom customer you are no doubt now aware of a security flaw in relation to their Netopia wireless routers. The security risk arises as a result of a combination of factors.

When a customer receives a Netopia wireless router, WEP encryption is enabled. WEP (Wired Equivalent Privacy) is a system of encryption that requires a user to enter a code (a 26-digit code in the case of Eircom of the form 879411b4f741e806a275565e16, which is a hexadecimal (base 16) number) before their computer can connect wirelessly to the router. When an Eircom customer receives a Netopia router, the specific 26-digit code will be provided to them, and known only to them, which allows them to connect to the wireless router. All good stuff to keep the bad guys out and your network private. So far so good.

In addition to a pre-assigned WEP encryption key, the customer's Netopia wireless router also has another pre-assigned parameter programmed into it called an SSID (Service Set IDentifier). The SSID is, in effect, the broadcast name of the wireless network which appears in the View Available Networks window. This can be anything you want but Eircom Netopia routers have an SSID of the format eircomxxxx xxxx e.g. eircom1242 9777. The problem arises due to the fact that the default WEP key and the part of the SSID after the eircom part are derived using the same algorithm. This has allowed some clever people to analyze the relationship between the WEP key and the SSID and come up with a small program called a key generator. Since the SSID is broadcast by default on the Netopia wireless router anyone can see the SSID of a router within range. All one needs to do to connect to that router is enter the 8-digits after the eircom part of the SSID into the key generator program and, voilĂ , the 26-digit WEP code is presented. Enter this code when required and you are connected to the network. PC Medic has seen this program in action and can confirm that it takes less than 1 minute to connect to a "secure" network.

What to do? It's actually quite simple to totally eliminate this security risk by either (a) changing your SSID or (b) changing your WEP code. Unfortunately, many customers don't feel comfortable connecting to their Netopia router to do this (Eircom should have contacted you if you have an "at risk" Netopia unit, and provided you with instructions to remedy the situation). If you're concerned and don't want to undertake this procedure on your own, contact PC Medic and we'll help you out.

2 comments:

Anonymous said...

Do you really think this is safer? Check on WEP encryption. It takes about 10min to crack it.
Regards,
Mike

PC Medic said...

Safer, perhaps not. Less likely to be cracked, yes. Most of the tools required for cracking WEP are Linux based and require use of specific network cards. Not that many people are walking around with Linux-based PCs. As for cracking within 10 minutes, that depends. The network must be transmitting packets that the crack tools can capture. If the network is idle it could take a lot longer than 10 minutes for sufficient packets to be captured to enable the WEP code to be cracked. The crack tool currently available for the Eircom WEP is available for Windows and you can also run it on your mobile phone. Once you have the pre-assigned SSID it takes 3-seconds to get the WEP code, even if the network is idle. So changing the SSID is a good idea. Of course using WPA is better still.

Since Eircom issued their caution some weeks past we have had only one request from a customer to set up WPA. Driving around South Co. Dublin I can tell you that the majority of wireless networks out their are Eircom based and the majority of their owners have taken no action to address the problem.