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Re: [LUG] File Sharing

 

On 16/02/18 22:35, Mark Williams wrote:
>> VPN servers are considerably more effort to implement and maintain
>> properly, but well worth it if you can.
> 
> I'm curious, would you suggest a VPN or tunnelling desktop traffic over SSH as a 
> more secure method to gain 'local' GUI access remotely? It's obviously possible to 
> do a lot via SSH but in the instance of wanting a desktop experience remotely, do 
> you think one creates a greater attack surface than the other?

VPN vs SSH usually comes down to other factors to be honest - either
properly setup should be easily "secure enough" and do whatever you need
it to. SSH more often than not is the flexible swiss army knife of
remote access but normally reserved for the highly technical (devs and
admins basically - you wouldn't let a normal user near SSH would you?!)
whereas VPNs are basically required for normal staff and non-technical
types. As for attack surface, hmm, I'm really not sure... I'd like to
say a single port SSHD instance seems like it has a smaller footprint
and probably way less lines of code to go wrong compared to a VPN, and I
*think* historically VPNs have had a lot more flaws in them as compared
to SSH but it's not like I've bothered to actually look up figures or
anything. Also I'm only really considering OpenVPN vs OpenSSH, and there
are a lot of crappy VPN products out there.

Ultimately SSH vs VPN - especially as SSH can actually provide VPN-like
transit as one of it's countless 'special tricks' normally ends up being
an architectural decision normally. Does the client want/need to do the
secure connection at Layer 2 or Layer 3?

> Do you think there's ever a case to use port knocking? I view it as a further 
> layer through which bad actors must pass, before gaining access to the desired 
> services. Not obscurity per se but a way of helping to mitigate bugs which 
> invariably exist in most services by increasing the complexity involved in gaining 
> unauthorised access to them in the first instance.

I do see what you mean to be fair - technically it is by definition
still security through obscurity of course but I get your point.
Especially if you're going into it with the full knowledge that it's not
truly increasing security but can have an otherwise useful effect then
who am I to say it has no value at all? I have also experimented with it
a bit myself over the years before losing interest a long time ago -
mostly as a "get out of jail" free card when fiddling with remote access
servers on a remote link where you're always worried you're going to
lock yourself out after a SSH restart or something. It didn't work very
well for that either, and it makes my iptables output look like hell.

> I changed the default SSH port for years before realising it was a stupid idea, 
> not least because of this: 
> https://www.adayinthelifeof.nl/2012/03/12/why-putting-ssh-on-another-port-than-22-is-bad-idea/

Oh hey, we've all been there - port X is getting battered on the load
balancer/VPN concentrator/firewalls/whatever... We'll just move the port
and remap all of our services! We're geniuses! Everything is solved! Who
needs stupid RFCs and standardised service/port numbers! Hooray!

[one hour later]

Waaah, why does nothing work properly anymore?! Why is sendmail on port
12345? Why is SSH bound to 4 different unprivileged ports?! You're all
fired!

The reason we've all stopped doing that is because it was really, really
dumb for a lot of reasons. I bet you still come across people even now
that *still* recommend it though!

Cheers
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