Sky Broadband advises customers to consider changing their default Wi-Fi passwords - because the apparently random network keys are guess-able.

The ISP issues customers with a wireless router that is pre-configured with wireless security switched on, and an apparently random network key. This sounds like a good plan. However, the key is based on the router's MAC address, which is broadcast "in the clear" - i.e in unencrypted form.

Reg reader James, who brought the issue to our attention, said that getting the MAC address is trivial and working out the algorithm that links it to a network key is "not exactly rocket science".

The security shortcoming affects only Sky Broadband's original router, a rebadged Netgear DG834GT, and applies only where customers keep the default network key. This leaves plenty of scope for problems. "With about a million Sky customers using the original DG834GT router, there's likely to be hundreds of thousands of Sky customers thinking that they're safe, when in fact they are not," James notes.

Sky has not issued a general alert, even though it was informed of the matter a month ago, through its SkyUser community support forum. "Sky offered advice to users on that forum, to either disable wireless networking, or change their wireless password, but they still haven't told their wider customer base about this problem," James said.

In response to our questions, Sky Broadband said users can improve security by changing their default password (as explained here), comparing this, more or less, to adding a lock to an already bolted door.

"A wireless router is great for flexibility and convenience but no one wants to unwittingly share their connection with another user. We pre-configure all our routers with security settings so that customers' bandwidth is protected from day one. Our website offers advice to customers on how to further enhance this level of protection by changing their default password to another of their own choice," a Sky spokeswoman told El Reg. ®

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