Hacker News new | ask | show | jobs
by geofft 3408 days ago
On the other hand, for a personal machine, caring about local root exploits is almost certainly outside your threat model. You have a https://xkcd.com/1200/ architecture, where everything other than software updates is running as uid 1000. The things you actually care about, your emails, your IMs, your tax documents, etc., are all accessible to uid 1000. Any random malware you might download will run as uid 1000. root is honestly a less interesting target. And the non-root account runs sudo often enough that an attacker with access to your account can get to root with a bit of patience, anyway, no kernel exploits required.

I used to maintain a laptop with two user accounts, one of which I used for running sudo and doing important work, and one of which had the Flash and Java plugins enabled and was used for Pandora, YouTube, etc. It sorta worked, but it was a pain, and I eventually gave up on it. If you do have a setup like this, then caring about local root exploits starts to make a bit of sense.

I now have a Chromebook, which sandboxes any attacker-controlled executable code on the machine. If you actually care about the security of your personal computer, do that, or get Qubes or something—and just use the vendor's provided OS and keep it up-to-date.
2 comments
blockoperation 3408 days ago
Multiple accounts can be quite usable if you get the separation right. Separate uids for personal emails/banking and porn browsing should be a given, at least.
link
kbenson 3408 days ago
At that point, why stop at separate uids and not just use separate virtual servers? It's a bit more costly in space and RAM (when running), but it's pretty good at reducing the attack surface. If you really want to be paranoid, restore from a snapshot every time you start the VM, and occasionally start it just to update it and create a new snapshot. Even if an attacker does get a local account, they have to do something useful with it before you close the virt, essentially destroying anything local they've set up.
link
jlgaddis 3408 days ago
firejail [0] looks interesting, though I haven't played with it yet.

[0]: https://firejail.wordpress.com/

link