Home Power Monitoring

powermonitor

Reader [john] finished up his home power monitor over the holiday weekend. It uses a pair of current transducers clamped onto the mains. These output 0-3V and are read by the Arduino’s ADC. The Arduino averages samples over a 20 second period, calculates power used, and uploads it using an Ethernet Shield. The shield can’t do DNS lookups, so he uses a WRT54G to negotiate with the remote webserver. He admits that the system could be more accurate; it can’t detect small loads like wall warts. He also says that money could be saved by talking serial to the router instead of over ethernet. Here are the current usage charts.

You can find many power monitor projects like this in out Home Hacks category.

D-Link Adds Captcha To Routers

D-Link is adding captcha support to its line of home routers. While default password lists have been abundant for many years, it was only recently that we started seeing the them implemented in malware. Last year, zlob variants started logging into routers and changing their DNS settings. It’s an interesting situation since the people who need the captcha feature are the ones who will never see it, since they won’t log in to change the default password.

[photo: fbz]

Apple Finally Fixes DNS Bug

With today’s release of Security Update 2008-006 Apple has finally addressed this summer’s DNS bug. In their previous update they fixed BIND, but that only affects people running servers. Now, they’ve updated mDNSResponder. Clients are no longer susceptible to DNS cache poisoning attacks thanks to the inclusion of source port randomization.

The Security Update addresses some other interesting bugs. Time Machine was saving sensitive logs without using the proper permissions, so any user could view them.

[photo: edans]

Black Hat 2008: Dan Kaminsky Releases DNS Information


[Dan Kaminsky]’s much anticipated talk on his DNS findings finally happened at Black Hat 2008 in Las Vegas today. [Dan] has already uploaded the complete slides from his talk as well as posted a short summary to his site. New information in the slides since our previous coverage includes “Forgot My Password” attacks and new attacks on internal network vulnerabilities as a side of effect of DNS cache poisoning. [Dan]’s talk today was over capacity; our shot of the conference room overflow is shown above.

Securing DNS On OSX


It’s been a few weeks since [Dan Kaminsky] announced the nature of the DNS vulnerability and allowed 30 days of non-disclosure for patches to be applied before details of the exploit went public. Unfortunately, the details were leaked early and it didn’t take long for a functional exploit to be released into the wild. Since then, many ISPs have taken steps to prevent their users from falling victim to the attack, and BIND, the widely-used DNS protocol implementation, was updated to minimize the threat. Even then, there were reports of a version of the attack being actively used on AT&T’s DNS servers.

Mac OSX uses a BIND implementation but as of yet, Apple has not released a patch updating the system (Microsoft, on the other hand, patched this up on July 8). As a result, machines running OSX are at risk of being exploited. Individual users are less likely to be targeted, since the attacks are directed towards servers, but it’s not a smart idea to leave this vulnerability open. [Glenn Fleishman] has published a way to update BIND on OSX manually, rather than waiting on Apple to patch it themselves. It requires Xcode and a bit of terminal work, but it’s a relatively painless update. When we tried it, the “make test” step skipped a few tests and told us to run “bin/tests/system/ifconfig.sh up”. That allowed us to re-run the tests and continue the update without further interruption. [Fleischman] warns that people who manually update BIND may break the official update, but he will update his instructions when it happens with any possible workarounds. Unfortunately, this fix only works for 10.5 but alternative, yet less effective methods may work for 10.4 and earlier.

If you’d like to know if your preferred DNS servers are vulnerable or not, you can use the DNS checker tool from Doxpara. As an alternative to your ISP’s DNS servers, you can use OpenDNS, which many prefer for its security features and configuration options.

DNS Cache Poisoning Webcast


UPDATE: Full audio of the webcast is now available

Today Black Hat held a preview webcast with [Dan Kaminsky] about the massive DNS bug he discovered. On July 8th, multiple vendors announced a patch for an undisclosed DNS vulnerability. [Dan Kaminisky] did not release the details of the vulnerability at that time, but encouraged security researchers to not release their work, if they did happen to discover the bug. On the 21st, the full description of the vulnerability was leaked.

In today’s webcast, [Dan] covered how he felt about the handling of the vulnerability and answered a few questions about it. He started out by talking about how he stumbled across the bug; he was working on how to make content distribution faster by using DNS to find the server closest to the client. The new attack works because DNS servers not using port randomization make it easy for the attacker to forge a response. You can read the specifics of the attack here.

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