Hi. I wanted to know if it’s needed to install a firewall on a linux desktop/laptop. Why yes or why no?
If your computer is connected to a network, I don’t see any downside of enabling a firewall. It’s a good security layer to have and costs basically no resources to keep running.
I guess a downside is having to fiddle with it, allowing stuff you want to get through. Sometimes it blocks stuff you don’t want blocked
I’d rather have to open up stuff my self then have an uninvited visitor doing it without me knowing about it.
Well sure, but I was commenting about the downsides
Yes, and hopefully you will have one preinstalled, blocking all incoming connections.
An outbound firewall like Opensnitch or Portmaster is also nice. But here I would say often you dont need one. Balena Etcher was the only App loading Ads, at all. Firefox and Thunderbird can be hardened. The rest is okay and doesnt phone home, Flatpak permissions ard also great.
There is no reason not having a firewall
Linux comes with a default firewall it’s called IPtables/NFtables, Just make sure that it’s on. Example I Ubuntu Sudo ufw enable.
Why not? It’s comically easy to set up one.
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If you allow the whole subnet you might as well not use a firewall. Your router has one and port forwarding is disabled by default.
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Yeah, I kind of agree. Unless this is a mobile device pretty much all traffic will come from within your subnet. I often deny incoming from my gateway (i.e. router) and poke holes as necessary.
ufw and docker don’t like each other
Can you elaborate on that? I’m curious what you mean.
I din’t have much time right now https://www.techrepublic.com/article/how-to-fix-the-docker-and-ufw-security-flaw/
It’s quiet old. Maybe it’s fixed now.
Thanks. So docker manipulates iptabels directly, thereby bypassing ufw rules. (Your previous comment was just really vague)
It’s also comically useless to have a desktop firewall application installed when you’re already behind some sort of firewall solution like a router not forwarding most incoming traffic.
It depends. Sure, maybe somewhat redundant for a home desktop that just stays at home on a network you control, but for a laptop it is absolutely essential.
You may also want a firewall to defend against other devices within your local network. Let’s say you have IoT devices, many of which are poorly secured and maintained by their manufacturers, or you live with family members or guests who don’t practice or even know about proper computing hygiene and are bringing in devices onto your local WiFi.
My IoT devices already have a dedicated network and guest can use my guest WiFi. But yes, you’re right. It depends. And especially for mobile devices some sort of local firewall solution could be relevant. If there are no ports exposed to the LAN you’re pretty save, though.
No you aren’t, browser based malware puts the attacker inside your fancy network. A basic firewall will greatly hinder any attack at basically no cost to you.
Some people like hosting some servers on their desktop as well, and doesn’t want others on their local network to access them. With firewalls, you can allow specific IP address to reach those servers.
That’s fine right up until something on your network, even the ISP modem-firewall-router-switch itself, gets compromised.
There’s incoming and then there’s outgoing traffic. Software firewalls can forbid processes that may be advertised as “offline only” from reaching out; typically a hardware firewall doesn’t care about this kind of thing.
I’d say if you plan on using it any public places, or if you don’t have full control over all the computers/technology in your home network, it’s a good idea to run one. It’s a nice last resort should someone on the same lan have a piece of malicious software.
Ironically enough if you do not know what a firewall actually does (and saying it “protects” against "stuff is NOT enough) IMHO you do need one. That being said unless you know what you are doing, better leave it to the default one with default settings.
Yes, because while I trust my device, I do not trust the Chromecast or the WAP to not be an asshole and fuck with things.
You shouldn’t trust your device. Modern software is insanely complicated, even netbsd had an rce.
Trust may be the worng word as Windows will be Windows but I know that no one is going to zero day my devices because I am not that high value of a target.
That’s a bad mentally as well. Most stacks these days are about quantity not quality. If you blindly hit 10000 targets it’s more profitable than trying to spear a single one.
Akin to not wearing a seatbelt because you are unlikely to be killed by a sniper
On a laptop absolutely. My firewall on my laptop doesn’t let me discriminate between networks so I’m always worried someone will try to attack me on public WiFi for the few ports I want open
On a desktop on a network you trust less important but still no firewall means if another device on your network gets compromised you’re screwed
For laptop, what kind of attack would we be protecting ourselves from? I get the relevance of antivirus, VPN, and device encryption, but what about firewall?
Any vulnerabilities in any of your software that can talk to a network, ssh, browser, the operating system itsself could be exploited if your firewall is down
If you’re using username and password and have ssh enabled, for example anyone on your network could attempt to log in to your machine
Let’s just say the system does not have any outward facing service (no ssh, http, smb, nfs).
At that point why not just have the firewall set to deny everything just to be safe though? There’s always the chance you missed something that’s decided to listen on some random port and if you aren’t using anything that listens on a network why have the firewall open anyway
For ssh, sure.
But a browser? No way.
My understanding is there can be a vulnerability in absolutely anything
Browsers are unlikely to but don’t think it’s impossible
A firewall protects open ports on your machine. A browser does not have any open ports.
Of course they have vulnerabilities, but a firewall won’t protect you from them.
If you have the ability to take a look at either SANS website, and see their articles, or have your system show you all the automatic attacks hitting your machine, then maybe you will understand…
Botnets are coded to hammer-away at all possible internet-addresses, trying to break-in & highjack more machines, to include in the established criminal-machine that the botnet is…
SANS said, a decade or 2 ago, that it took, on average, something like 6 or 4 minutes for a new MS-Windows machine to be owned by some attack from the internet.
I’ve had linux machines cracked/owned, and wiped 'em to get 'em clean.
Having no immune-system is BAD.
Linux botnets, apple operating-system botnets, they exist.
I don’t think there is any operating-system that is connected to the internet that doesn’t have attacks coded to crack it.
I just looked at SANS.org, and they have totally changed, so they are now … more a moneymaking-machine wanting B2B biz?
Here, though, are some cheat-sheets they made:
https://www.sans.org/posters/?msc=main-nav
They used to tell us the top-20 most effective protections for particular threats, identifying how prevalent the threats were, etc…
No idea who does that nowadays…
Do you need a lock on the door of your place?
No, but it’s a damn good idea to protect whatever is in it.
That’s a bad comparison. Without a lock you can just open the door from the outside.
But… Is it?
It’s not.
If you have a house, it has a door which you can use to access everything inside.
If you have a linux install with no services running on it, it has no doors, and thus doesn’t need any door locks. And if it does have services running on there (which run publicly), it now has doors, sure, but getting one of those doors open doesn’t guarantee access to the whole house - usually it’s gonna be an empty room
Linux with no services? That’s not a usable system for anyone who would ask “do I need a firewall”
Systemd is a service that runs logind. What are you doing without them?
I think by services they mean self-hosted, web-based services, or things like sshd - services which work by actively serving connections on a particular port or ports.
And even then, a properly configured SSHD instance wouldn’t really benefit from a firewall, unless you wanted to block all countries besides your own or something.
You most likely already have one installed, but not enabled. It doesn’t harm anything (maybe you need to allow traffic to ssh or other configuration, but after that you’re all set) and it’s a layer of protection, specially if you need to move between networks (public wifi etc).
On Mint the firewall is enabled by default. Setting up firewall rules is pretty easy though, so it’s worth taking five minutes to read up on it.
A sane firewall configuration should have no/minimal impact on a desktop focused OS.
On the other hand, sometimes programs are really badly made and expect stupid things like there being no firewall.
You should have one yes, but to each their own.
I manage a bunch of windows computers and regularly make adding firewall rules part of install scripts, good example: Dreamweaver.
If you are only at home you don’t need it because the router already has a firewall. But if you’re is using public WiFi definitely use it.
It depends on how much do you trust your router.
Some home routers have poor security: unfrequent updates, http (not https) web consoles, single factor authentication (password only, without username for instance).
Enabling your firewall is the bare minimum, costs nothing and it’s a good security practice.
It depends on how much do you trust your router
Your router and every single device connected to your local network.
Sure that is true but if you’re getting it from the ISP and it’s that bad, you need to change ISP.
Plus, ALWAYS get into the router and set a new password. Always. And go over all the settings to be sure. As you say, a shit ISP may have lax security.
Changing an ISP is very rarely an option. That’s why they pull the shit to begin with.
You should bring your own hardware wherever possible. I’d never trust my local network to the ISP.
you need to change ISP.
You say that like its easy. It usually isn’t.
It usually isn’t too hard to insert your own router into your network setup. You might have to battle with ISP support a bit though, but a ton support either Bridge Mode or IP Passthrough.
I’m now sure how is is in your country but where I live we don’t have a contract with the ISP. We just pay monthly and at any time we can cancel. But if you have a contract, then yes you’ll need your own router ideally
In my country all ISP routers suck hard. I can change ISP but it doesnt help at all. You have to be lucky to get a working router it seems. We can get service with no contract with extra €, but you still have to use their router that doesnt support bridge mode. Im not even talking about routers security
Yes, because you can forget what services are running and maybe they can be explited.
An example can be Syncthing which setting are done via web browser at port 8384. If you do not have a firewall, everyone on the same network would be able to change Syncthing settings and then sync your directories to their devices.
Good point, but syncthing only listens on localhost as others have said too.
However it still is a network service that can have vulnerabilities, besides many others like KDE Connect (which may be a target as one of its purposes is remote control and monitoring) or a bittorrent client
Eh, the router acts like one. I have no open ports. On a laptop you use on the go I would use a firewall tho.
