Don’t leave your laptop in the pub

December 9th, 2016 by

After about twenty pages of awesome beers, you discover they also have mead.

After about twenty pages of awesome beers, you discover they also have mead.

Last night we had our Christmas party. For a 24/7 operation, that means we have to have at least one laptop with us at the party. We had just one urgent customer issue which we dealt easily without ruining the night.

However, in addition to taking your laptop to the pub, Pete would like to remind everyone that it’s equally important to remember to take your laptop home from the pub too, as he didn’t. This means we have to have a brief security review to evaluate the risks of briefly losing a company laptop. Ten years ago when we had tens rather than thousands of servers, this would have resulted in a revocation and replacement of the company ssh key on every server under emergency conditions (and those of you with an unencrypted AWS key might worry about total company deletion).

Over the past decade we put more effort into improving our security. The laptop contains an encrypted filesystem, on that filesystem is an encrypted ssh key which will allow someone into our jump box. If they’ve worked out the password for the filesystem, and the password for the ssh key,they then also need to guess password on the jump box before they would be able to access customer or company systems. That’s three different passwords to guess, or two encryption breaks and one password to guess. The passwords are not chosen by the user, the come straight from pwgen and the random number generator. Whilst we’re not worried, we’ll do some extra monitoring the logs on the jump box for attempts on Pete’s account.

Of course there’s also a risk that someone physically tampered with the hardware to install a key-logger in between leaving it in the pub and recovering it the next day. The laptop passes a brief physical inspection. If it has been tampered with, it has been tampered with very well. If our attacker was sat in the pub with a spare key logger kit just in-case the laptop was left behind, it would have been easier and cheaper to stage a break-in at an employees house, or to have forced them to check their hand luggage on a flight, or to have installed the key logger before the laptop was bought, or maybe to have compromised the random number generator in any or all of our servers before they were bought. So our threat model remains relatively unchanged and we don’t think we’re under significantly more risk today than we were yesterday.