By Joris Evers
Staff Writer, CNET News.com
February 15, 2007
If you haven't changed the default password on your home router, let
this recent threat serve as a reminder.
Attackers could change the configuration of home routers using
have discovered. The researchers first published their work in December,
but Symantec publicized the findings on Thursday.
The researchers found that it is possible to change the DNS, or Domain
Name System, settings of a router if the owner uses a connected PC to
attacker divert all the Net traffic going through the router. For
example, if the victim types in "www.mybank.com," the request could be
sent to a similar-looking fake page created to steal sensitive data.
"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.
The attack works on any type of home router, but only if the default
router password hasn't been changed, Ramzan said. The malicious
using the default credentials--often as simple as "admin" and
"password"--and changes the settings.
"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.
In crafting their proof-of-concept attack code, Ramzan and researchers
at Indiana University built upon earlier research that showed how
chief technology officer at WhiteHat Security, demonstrated how
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.
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