10mo ago

Browse safely on corporate laptop

I work on a corporate laptop that has an infamous root CA certicate installed, which allows the company to intercept all my browser traffic and perform a MITM attack.

Ideally, I'd like to use the company laptop to read my own mail, access my NAS in my time off.

I fear that even if I configure containers on that laptop to run alpine + wireguard client + firefox, the traffic would still be decrypted. If so, could you explain how the wireguard handshake could be tampered with?

What about Tor in a container? Would that work or is that pointless as well?

Huge kudos if you also take the time to explain your answer.

EDIT: A lot of you suggested I use a personal device for checking mails. I will do that. Thanks for your answers!

38 comments

Don't. Just fucking don't. Keep your personal stuff off your work equipment and vice versa. I don't know why people keep wanting to do this, because it only leads to trouble.
- Adding on:
  Anything you do with a company device brings liability to them, which is part of why you should keep things separate, and part of why they manage devices.

The best thing is to use a different device, period.
Since the company is lord and master over the device, in theory, they can see anything you’re doing.
Maybe not decrypting wireguard traffic in practice, but still see that you’re doing non-official things on the device that are probably not allowed. They might think you’re a whistleblower or a corporate spy or something.
I have no idea where you work, but if they install a CA they’re probably have some kind of monitoring to see what programs are installed/running.
If the company CA is all you’re worried about, running a browser that uses its own CA list should be enough.
- Yeah, I'll use my own device, log on to the guest network and start Wireguard on my laptop. Seems a fair choice both for the company and myself.
  
  That seems more sensible.
  But they still can track some of the things you do (same with any untrusted wifi network):
  all data of http traffic (i.e. non-https)
  ip addresses you connect to
  hostnames you connect to (if SNI is not working correctly)

Personal stuff on personal devices.
Company stuff on company devices.
Never mix. I don't even check my personal email on my work laptop.
If I need access to my home, it's through an external connection like LTE.
- This, but if you use an OS like Qubes then you can keep them separate while still using the same device
  
  I think that with 802.1X you can't do that unless you export the keys somehow.

You wouldn't do this with a stranger's device, so why insist you do it with your employer's device? Just don't.
If you have a workstation and want to use the same monitors/headsets/peripherals with both the company device and your personal device try one or two KVM switches.
- Power toys and mouse without borders would like a word

Don’t. And beyond that if you use their WiFi, connect to a VPN. Best just use LTE.

What you are wanting to do is likely a misuse of corporate resources. If you are still unsure go talk to IT

Use a tails usb
Preferably just dont though
- I'd its tails then its not an issue at all. Its using the same keyboard but for all intents and purposes, its a different machine

If it boots from USB, boot a different OS. But overall, preferrably use a different device.

If you want to use the same physical device just put Linux on a bootable USB stick and boot off that
- Do not do this if it let's you. Its a good way to get in trouble
  
  I’ve done this in the past without apparent issue. Could you perhaps expand on where the risks arise here? My impression was that unless there is some independent hardware running code separate from the OS, then it would be OK?

Just run portable Firefox without the root cert?
- .
  
  It's good to know that they can't bypass wireguard or Tor. I was a worried about that.
  As others have suggests, I will probably use a separate device to check my mail. That seems the safest and fairest option both from the company and my perspective.
- I tried opening a browser in a Docker container and but couldn't browse any site except google because it didn't recognize the CA authority.
- Often gets blocked. I tried on my work and you can't use any other browser.

What I did is use a ssh tunnel and rdp over that. ssh and RDP are both build in to windows. VPNs often don't work because some software needs to be installed.

The computer probably has local security tools (such as an edr) that spy on you any way.
You need to assume it is completely compromised.
But... assuming this isn't in violation of your company computer usage policy (which it very much might be and can put you in trouble) you can install any VPN (avoid spyware shit) and a different browser (ideally something a bit obscure, like librewolf) and this will bypass the MiTM as the the device that does the MiTM would be either:
A) a network device that hijacks the HTTPS requests (VPN bypass this)
B) the browser used by the company
C) some other kind of software that atteches itself to all browsers via admin installed extensions (obscure browser might not be recognised by such software, be sure to check the installed extensions after letting the browser run for an hour)
And once you are done you can check the certificate chain in the browser to confirm.
- Before I wrote this thread, I ran for a couple of minutes a browser from a docker container. I couldn't browse any website because of the missing CompanyName CA certificate. So, I stopped because it was too freaky.
  
  That makes sense, the MiTM was still going on but you browser was not configures with the company CA

Either double-fist with a second laptop or install QubesOS on your laptop

Don't use the company laptop, you can only confirm what is going on with your own devices

Use your company laptop for only work....
If you install non-approved software you will probably get flagged by the security team.

38 comments