At work recently moved from our own office space to a coworking space. Bryan said, "remember to lock you laptop screen when you're not using it." I said, "I use Mobile Mouse so I can lock it with a hot corner from across the room."

He asked, "How does Mobile Mouse connect?"

The importance of the question was obvious. I knew it was wi-fi, and the wi-fi is shared with the rest of the coworkers. Surely anything that can remote control my computer will be a secure connection, right? Right? The docs said nothing, so I fired up a packet sniffer.

$ sudo tcpdump -i en0 -w mouse.packet port 9090 [ connect with Mobile Mouse, mouse around a little ] $ strings mouse.packet

What did I find? Here's a sample:

WELCOME CONNECT my-password-in-plain-text C97B5F9F-1840-4546-AFD9-AA90FEE09FE4 rjbsPhone CONNECTED jubjub Welcome A4:5E:60:BB:12:11 10.10.5 SETOPTION PRESENTATION SETOPTION CLIPBOARDSYNC HOTKEYS APPICON Finder /System/Library/CoreServices/Finder.app [ a bunch of base64-looking stuff; I think it's the Dock icon images ] MOVE 1.50 -8.50 MOVE 4.50 -12.00 ...

There's my phone's device name, the password, my laptop's name, and a bunch of other identifying information. Anybody who sniffed the network for a while could find this traffic and then remote-control my laptop when I looked away. (Or, more amusingly, when I wasn't looking away.)

I asked the makers of Mobile Mouse why they didn't use a secure connection, and whether they would. They said, "Well, it's really intended for a secure local network, but we'll think about adding this feature." Still, they link to people who review this device as a presentation remote. This sounds like a recipe for at least hilarity, if not disaster. "Hey, the consultant is presenting with his phone on the guest wi-fi. Let's sniff it!"

My point here is not that Mobile Mouse is bad software. It's really good software with this one enormous flaw. My point is that nobody really cares about protecting you except for, hopefully, you. You had better pay attention!