I'm currently at SFO, San Francisco's main airport, waiting to fly back to Sydney. Thanks to the mysteries of international flight scheduling, I arrived from Vancouver so early that the Qantas check-in desk didn't open for another four-and-a-half hours, which left me plenty of time to peruse the International Terminal.
When you have to wait several hours in order to queue up for a chit to wait several more, what better to do than to take advantage of the airport operator's generous 45-minute free WiFi allowance? At SFO, they don't begin timing you until you agree to the Terms And Conditions, which is just as well, because they are rather lengthy - just under 3000 words - and include some interesting surprises.
One is the requirement that, once issued an IP number via DHCP, "you shall not program any other IP address into your device". (Not even to set localhost to 127.0.0.1?) Another is that "you agree that we may access your Device and information stored on it [...] to enable, operate and update [our] Service."
That Term And Condition sounded dangerously broad to me, so I decided not to agree. I also wondered, since I use a Mac, what sort of access the numerous Mac users around me in the food court might be giving away, by default, to the operators of the wireless network.
Quite a lot, in some cases. Above, you can see a Mac with openly readable shared folders, and a number of other nearby Macs with the Mac Drop Box enabled - a directory to which other people can write to make file sharing really easy.
If you have enabled file sharing on your Mac (click the System Preferences... option in the Apple menu and choose Sharing to check), you should do these two things:
1. Run an up-to-date anti-malware program. Yes, I know you have a Mac, and that received wisdom says that "Macs can't get viruses". But they can get viruses, and they can also pass them on to unsuspecting friends and colleagues. If other people can dump files of their own choosing on your computer, you are most definitely at risk.
2. Download and install the latest updates from Apple (use Software Update... from the Apple menu). Security Update 2010-006 fixes the CVE-2010-1820 vulnerability, through which unauthorised users may be able to download files from your Mac, even if they are protected with a password.
This latest security fix, and more, is covered in fellow-blogger Chet Wisniewski's latest podcast, which is well worth a listen here:
You can also download this podcast directly in MP3 format: Sophos Security Chet Chat 28