Wi-Fi Networking News reports that a consultant has discovered a "moderately critical" security vulnerability in the Linksys WRT54G router. According to the report, the Linksys WRT54G "allows remote, over-the-Internet administration login even when remote management is turned off." This means that an automated attack could be mounted against WRT54G routers that were installed in their default configurations.

If an attack of this nature were to occur, it would pose an inconvenience to users who are accustomed to being able to use WRT54G routers for LAN or Internet access. The router could be reconfigured so that it was unusable by the people that originally installed it. Under that circumstance, control of the router could be regained by performing a "hard reset".

A more sophisticated attack might involve parsing the HTML from the WRT54G administrative interface to recover WEP or WPA keys. The existence of such keys would mean that the configuration had been changed from the default, however. It's unlikely that a user would turn on WEP or WPA and leave the admin password set to the default.

In any case, it's a very good idea for WRT54G users to review the configuration of their routers at this time.