Posts Tagged ‘dns’

An update to my post from last week regarding vulnerabilities in WiFi access points …

Team Cymru, a non-profit security research organization, recently reported that some TP-Link wireless routers had been compromised in such a way as to redirect the DNS (Domain Name System) requests to a couple of suspicious IP addresses.

Without going into the technical details of what this means the effect would be that a hacker could reroute traffic from those home networks to a destination of his choosing. In other words, a user types “www.” into their browser and ends up instead at “” or some such. Scary stuff since we all depend on the DNS to get us to the correct web sites, connect to our email and so forth.

Team Cymru then updated their findings this week to reveal that they have identified more than 300,000 such home routers that have been compromised and the list includes not only TP-Link models but also those from D-Link, Micronet, Tenda and more.

My previous post focused on Linksys equipment so, as you can see, the larger problem of vulnerable WiFi access points and routers runs across the various manufacturers. In other words, don’t think you’re safe just because your particular make and model hasn’t been explicitly listed so far. It’s probably just a matter of time.

So now that we know the risk is real and not just theoretical, what should you do? Here’s some good advice from Team Cymru as summarized by PC World:

“Team Cymru researchers advise users to disable remote management over the Internet on their routers and to keep their firmware up to date. If remote administration is absolutely necessary, steps should be taken to restrict remote access to only particular IP addresses. Other recommendations include: changing the default passwords, not using the default IP address ranges for a LAN, logging out every time after accessing the router interface, checking the router’s DNS settings frequently to ensure they haven’t been modified, and using SSL (Secure Sockets Layer) to access the router’s Web interface if the option is available.”

Hopefully, one day all our routers and access points will be able to securely patch themselves as we have done with Windows, OS X and others, but until that happens, you now at least know what to do.

Who can you trust?

Posted: June 11, 2012 in Uncategorized
Tags: , , ,

That’s a difficult question to answer — especially when you’re dealing with organizations you know only over opposite ends of a wire. This issue lies at the heart of an article quoting me in today’s Raleigh News & Observer “Stump the Geeks” column.


First of all, let me state for the record that I have no firsthand knowledge of the service offering discussed in that column of this blog post or how well their service works. It could be perfect in every way, for all I know, but the issues I’m focusing on here remain the same so please read this in the spirit in which it was intended — as an example of how some of the critical thinking that needs to be employed when dealing with security issues.

With that bit of disclaimer out of the way let’s consider the case of OpenDNS. Typically the translation of that web site name (e.g. into it’s numeric IP address equivalent, which is necessary in order to actually route your request through the network, is handled by a Domain Name Server (DNS) that is provided by your ISP. OpenDNS, however, offers to do this for you instead if you are willing to configure your system to use its services in lieu of the one your ISP provides.

Why would you want to do this? Well, it’s because OpenDNS claims to be able to offer additional controls and security protections that most ISPs don’t. For instance, you can configure OpenDNS to block access to harmful sites based upon objectionable content or security risks by redirecting traffic to a safe landing page rather than the actual site.

Sounds good, right? But who determines what is risky and what isn’t? Do their definitions coincide with yours? With the way “bad” sites pop up and disappear on the Internet on an hour-by-hour basis, can any system based upon reputation (such as OpenDNS) ever hope to keep up with the perpetual game of Wack-a-Mole?

Further, even if all this does work perfectly well, who do I trust more — OpenDNS of my ISP? The reason this last question is important is that one or the other is going to have access to all my web surfing history. If that bothers you then you need to decide which of the two choices in this example, do you trust more with that information? Either could be compelled to turn over such information if directed to do so by the Courts but what about turning it over to other companies who use it to market to you based upon your browsing habits?

I have no idea how to answer that question for you since my sensitivity to risk in this area is bound to differ from yours. It’s the same reason you choose to bank or invent with different companies than I do as well. It’s a very personal choice but, in the end, it all comes down to … “who can you trust?”