Slowloris HTTP denial of service

denial of service technique that can take down servers more effectively. Traditionally, performing a denial of service attack entailed sending thousands of requests to a server, these requests needlessly tie up resources until the server fails. This repetitive attack requires the requests to happen in quick succession, and is usually a distributed effort. However, [RSnake]’s new technique has a client open several HTTP sessions and keeps them open for as long as possible. Most servers are configured to handle only a set number of connections; the infinite sessions prevent legitimate requests from being handled, shutting down the site. This vulnerability is present on webservers that use threading, such as Apache.

A positive side effect of the hack is that the server does not crash, only the HTTP server is affected. His example perl implementation, slowloris, is able to take down an average website using only one computer. Once the attack stops, the website will come back online immediately.

Global hackdays: tangible interfaces

Trackmate :: 5 ways to get started from adam kumpf on Vimeo.

June 6th is the date of the upcoming Global Hackday. This time, focusing on cheap tangible interfaces, mainly trackmate. They want as many people to join as possible, even if you’re not comfortable with code. We’ve covered the construction of the trackmate surface before, now build one and get in there and contribute.

sslstrip, hijacking SSL in network

Last week at Black Hat DC, [Moxie Marlinspike] presented a novel way to hijack SSL. You can read about it in this Forbes article, but we highly recommend you watch the video. sslstrip can rewrite all https links as http, but it goes far beyond that. Using unicode characters that look similar to / and ? it can construct URLs with a valid certificate and then redirect the user to the original site after stealing their credentials. The attack can be very difficult for even above average users to notice. This attack requires access to the client’s network, but [Moxie] successfully ran it on a Tor exit node.

Time’s poll hacked

Though Time won’t admit it, their poll on the most influential person was hacked. Moot, the founder of 4chan is rated #1. Not only that, but if you read the first letters of the poll results, you get “Marblecake also the game”. This refers to the IRC Chanel where many 4channers congregate as well as “the game” an internet meme. This article is very interesting as it delves into the details of the attack. Focusing mainly on what happened when the autovoting software was shut down due to reCaptcha. you’ve probably seen reCaptcha before. It presents you with two words, made difficult to read by strange kearning, warping, and squiggles. If you can read it, you’re most likely a human. Anon, a common name for 4channers, first tried to hack reCaptcha.

Their attempt at hacking reCaptcha relies on the process reCaptcha uses to identify words. It presents you with two words, one of which it already knows. The other is compared to a database of common responses to that word. Anon decided that if they entered “penis” enough times, they could flood the database allowing their autovoter to function again. This, though clever, was unsuccessful. They eventually settled on manual voting. This was taking too much time, they feared they would never reach their goals. To help with this, they built a simple interface that would preload several reCaptchas and cue up votes. This streamlining allowed them to squeak in the votes they needed to accomplish this.

It’s also worth noting that Time didn’t close the vote entries when the poll closed. They removed the poll from their site, but the streamlined vote software was still working. Anon is a powerful force of nature. If only we could harness it to cure cancer or HIV.

WaitLess bus tracking system

Bus systems on campus can often be frustrating. You’re standing at the stop waiting and you don’t know if it would just be faster to walk. If you have a WaitLess tracking system at your stop, you can see exactly where the bus is and make that decision much easier. The unit is self contained, solar, and equipped with wireless internet. With an Arduino at it’s core, it displays the current location of the bus by lighting an LED on a map. You can see a video of it in action after the break.

Defcon 17 Call for Papers

Notorious hacker conference Defcon has just published their Call for Papers. The 17th annual event will happen July 30th through August 2nd. Most of the announcement is the same boilerplate they’ve included for the past two years. Like last year, they’re not defining the specific speaking track themes and will come up with them based on submissions. New for this year is a half-day of workshops on the Thursday before Defcon for anyone that’s showing up early. This pre-con event is targeted at newbies. It certainly sounds like an interesting way to ease into Defcon instead of the usual delays and fire marshals. We’ve been attending every year since 2005 and love seeing new things. You should definitely consider presenting this year (we want to see more hardware!).

BackTrack 4 Beta released

The Remote Exploit Development Team has just announced BackTrack 4 Beta. BackTrack is a Linux based LiveCD intended for security testing and we’ve been watching the project since the very early days. They say this new beta is both stable and usable. They’ve moved towards behaving like an actual distribution: it’s based on Debian core, they use Ubuntu software, and they’re running their own BackTrack repositories for future updates. There are a lot of new features, but the one we’re most interested in is the built in Pico card support. You can use the FPGAs to generate rainbow tables and do lookups for things like WPA, GSM, and Bluetooth cracking. BackTrack ISO and VMWare images are available here.