Welcome lifehacker.com & hackszine.com visitors. Read this follow up post if you care about the story of this article.

Update 06:20pm: My luggage just arrived - I'm happy ; ).

Yesterday I left Atlanta, GA after having spent 6 weeks of my summer there to visit my host family that I was staying with the year before as a foreign exchange student. The flight back wasn't all that great, it had 4 hours of delay, I missed my connection flight, had a long waiting time at the Düsseldorf aiport and when I finally got back into Dresden my 2 big suit cases were missing - and still are. But oh well ... they'll show up, eventually.

Meanwhile I want to share a little hack I did when I was waiting at the Atlanta airport. As most airports do these days, they have a wireless network there. Unfortunatly, they try to make you pay $7 for 24h, no matter how long you actually get on there. Since I didn't want to get ripped off, I started playing around with the network. Using LiveHTTPHeaders for firefox, I was able to see that they were redirecting me to their portal via a 302 whenever I tried to access a public site. So the first thing I tried was to deactivate redirects in the about:config, and hoped they would send me the site I wanted after their redirection header. This might sounds stupid, but checkout the post on cakebaker talking about it if you are unfamiliar with the problem. Anyway, it didn't help, I wouldn't see any page at all, and instead get a firefox error message. So back to the beginning.

I continued to try a couple other things, like checking if they eventually forgot some ports like 21 (ftp) or 110 (pop3). But no, all of them were properly blocked. After a lot of unsuccesfull attempts, I had some intuition telling me to check how they handle pictures. Without any hope of success I typed http://www.google.com/.jpg into my browser's adress bar, and to my big surprise I saw the page you see when you follow the link right now. The next thing I typed in was: http://www.google.com/?.jpg but that didn't work. But I went on, and found that url's like http://www.google.com/search?.jpg worked like a charm. I found that I could easily visit sites like slashdot, google, or even this weblog, when adding a ?.jpg at the end of the url. The next logical step was to automate that. I downloaded greasemonkey.xpi?.jpg (*g*) and wrote a 4 line js script that would add ?.jpg to every link in a document. That way I was able to browse most sites without a hassle. Unfortunatly, I didn't get to explore this vulnerbility much more, because I had to board the airplane, were I waited another 3 hours due to a mechanical failure - without wlan : /.

So, anyway, wish me good luck with getting my luggage back and if you are ever stuck at an aiport with commercial rip-off wlan only, you might want to give this little method a try ; ).

--Felix Geisendörfer aka the_undefined

Update: Read this follow up post if you care about the story of this article.

