Users of Britain's most popular Wi-Fi router have yet another reason to change the default settings toute de suite, and once again they have the folks in BT's security department to thank.
In recent weeks, they changed the default password in the BT Home Hub, from "admin" to the device's unique serial number. In theory, this should improve user security by making it next to impossible for intruders to guess the credentials to gain administrative control of the combination modem and wireless access point. And this could only be a good thing, in light of the many security vulnerabilities (for example, here, here and here) exposed in the device over the past seven months.
But it turns out the BT Home Hub is only too happy to volunteer its serial number, according to GNUCitizen, an ethical hacking think tank. Requests sent to the device's multicast IP address (184.108.40.206) are promptly answered.
Of course, such requests can only be sent by a machine connected to the local area network, but getting access isn't as hard as you might expect: The BT Home Hub defaults to the woefully inadequate Wired Equivalent Privacy (WEP) to secure itself. And even when users opt for the more robust Wi-Fi Protected Access (WPA) the device uses a weak algorithm to generate keys that could enable attackers to crack the protection when the default encryption key value is used.
BT has taken a fair amount of flak for the security of its router, and it seems likely the decision to change the administrative password was made to quell some of the criticism. The episode is yet another reminder that security isn't something that can be tacked on as an afterthought.
For now, it's important to know that the default security settings won't keep you safe. The only way to lock it down is to follow these instructions. The typical Reg reader should have no trouble, but think of the average BT user. Bailing out a leaky rowing boat doesn't do a lot of good if you don't take time to plug the hole first. ®