Ability to change the settings of poorly configured home routers could put home networks at risk of serious attack.
"I have been able to get this to work on Linksys, D-Link and Netgear routers," Symantec researcher Zulfikar Ramzan said. "You can create one Web site that is able to attack all routers. My feeling is that it is just a matter of time before phishers start using this."
After a router's DNS setting is changed, all computers connected to the device will use the DNS server set up by the attacker to find their way on the Internet. DNS functions like the phonebook of the Internet, mapping text-based addresses such as www.news.com to actual numeric Internet Protocol addresses of a Web site.
"One of the issues is that the set-up steps in the router don't prompt you to change the password," Ramzan said. As a result, many people never properly configure their networking gear, he said.
Grossman is impressed by the Symantec and Indiana University work. "This is very dangerous stuff and could be highly effective if used in the wild," he said.
Router makers already know of the problems with default passwords as well as other security concerns, they said. Linksys, for example, recommends that customers change the default password during the installation procedure, said Karen Sohl, a representative for the company, a division of Cisco Systems. "We are aware of this," she said.
On its Web site, Linksys warns users that miscreants are taking advantage of the default passwords. "Hackers know these defaults and will try them to access your wireless device and change your network settings. To thwart any unauthorized changes, customize the device's password so it will be hard to guess," the company states.
Still, although Linksys' software recommends the password change, consumers can either plug in their router without running the installation disk or bypass the change screen, keeping the defaults. The company offers detailed information on how to change the router password on its Web site. Netgear and D-Link also recommend password changes.