Sys-net disposable? (4.1 rc)

[tripleh]

When you connect to a Wifi, network manager stores all connection details inside /rw/config/NM-system-connections/[wifi].nmconnection.

Just copy that file to the hopefully dedicated template of your disposable sys-net and your disposable sys-net will work with it on next boot.

The same applies for all the other modifications that need to remain persistent. Do them inside the template. You can see from mount what is persistent in your template (everything on /dev/xvdb).

[qqubes]

@yann

That’s possibly sufficient for most of us. In theory though, the something can still persist by reflashing any firmware on the network cards attached to sys-net , and making the VM disposable does not help with a thread of that level of sophistication.

If the network card firmware is compromised could it potentially give the attacker access to other VMs, such as vaults that are not connected to sys-net?

[fsflover]

@qqubes

If the network card firmware is compromised could it potentially give the attacker access to other VMs, such as vaults that are not connected to sys-net ?

Potentially, yes: QSB-081: x86: MMIO Stale Data vulnerabilities (XSA-404) | Qubes OS.

[tanky0u]

@alzer89

You’ll basically have to enter in passwords/keys every time you start sys-net . Some people consider this an inconvenience.

I think having a password manager (like pass) in a vault containing the wifi passwords that you frequent to, helps with this inconvenience.

[qqubes]

@fsflover

Potentially, yes: QSB-081: x86: MMIO Stale Data vulnerabilities (XSA-404) | Qubes OS.

Interesting! So the answer would be no, but for these security exceptions.

Are there known attacks on PCI firmware over a network (i.e. without physical access to the system)? Any way to protect against them?

[qqubes]

@fsflover

Potentially, yes: QSB-081: x86: MMIO Stale Data vulnerabilities (XSA-404) | Qubes OS.

Following XSA-404, I did sudo qubes-dom0-update --enablerepo=qubes-dom0-security-testing which installed the qubes-core-dom0-linux-4.1.23 package. Then cpu-microcode-info revealed that I have the 2022-05 update installed.

It would be very helpful to know: Was this update installed after I did the dom0 update, or does this mean it was already updated by some other process?

The XSA seems to say that the updated package qubes-core-dom0-linux-4.1.23 is only providing information, not new microcode.

[Narvey]

@trounces

I cannot enter only my home WIFI password into the disposable sys-net template so I get the best of both worlds, no persistence after reboot but it does remember the one or two most frequently used networks? Or would that defeat the purpose?

This is possible, but not necessarily recommended:

1. As root, in (sys-)net:

cd /etc/NetworkManager/system-connections/
qvm-copy *

2. Punch in the name of your disposable template and hit OK.
3. As root, in the disposable template (sys-)net is based on:

cp /home/user/QubesIncoming/*/* /etc/NetworkManager/system-connections/

(If you have copied anything else to this qube, or if you only want to copy one or two network configs, replace those stars with something more accurate)

Before doing any of this, make sure you are OK with broadcasting those SSIDs (and maybe passwords?!?) as alzer mentioned.

[bayesian]

Also don’t forget to make the .nmconnection files in then /rw/config/NM-system-connections/ folder to have the user root and group root as the owner:

chown root:root /rw/config/NM-system-connections/*.nmconnection

in you Disp template of sys-net-dvm.

I’ve been debugging this mdf for the past 3 hours.

[Narvey]

you mean chown? so:

sudo chown root:root /rw/config/NM-system-connections/*.nmconnection

[bayesian]

Yes thanks for the correction. I’ve edited it.

[Narvey]

Well now we have a working process to save wifi passwords (and persist network info) across reboots of a disposable (sys-)net qube. Just use @bayesian 's path and not mine in the disposable template (for me, fedora-36-dvm).

[enmus]

Actually we had it already multiple times already

Convert sys-net to disposable

I would never, ever, ever, never connect online any qube that has template in it’s prefs/name, hahah. Actually, my default netVM is none. Setup connection in sys-net dispVM and while it’s still on, fire up it’s dvm-template and copy correspondent .nmconnection from sys-net to /rw/config/NM-system-connections folder of a dvm-template. Shutdown both, and restart sys-net. That way, it’ll persist across reboots.

But this topic wasn’t about that.