Are Consumer Firewall/NAT Boxes Really Secure? 166
blate asks: "Consumer-grade Firewall/NAT devices, such as those from Linksys, Netgear, D-Link, etc., have become very popular as more and more users get broadband connections. I've been using a Linksys router at home for several years and have never had any security problems. But how secure are these devices, really? The firewall guru's I know argue that a NAT really doesn't give you much beyond security-by-obscurity. What are your experiences with this (have you ever been comprimized through such a device)? Would I be better off with a Linux/ipchains firewall?"
Good, but not "plug and forget." (Score:5, Insightful)
It's true that Most of these units are flash upgradable, but consumer-level network gear's support lifecycle tends to be pretty damned short. It's quite likely that the company producing the hardware isn't going to be bothered to repair a product, even if it's proven to be as permeable as a sponge.
My personal take would be that these units are great, so long as you learn a little about how they work. Shoot for something that's based on Linux or another OS with public information, learn what kernel it's using, and then treat the unit just like a PC running that same release. If an exploit is announced for that version of Linux, get it off the wire until you can patch it, just like you'd do with the real PC.
Re:Good, but not "plug and forget." (Score:5, Insightful)
> isn't going to be bothered to repair a product
Now that's a platitude if ever I've seen one. What precise personal experience do you base this statement on? Linksys, Netgear and SMC certainly have a decent track record of supporting their products, sometimes well into the next few generations. Besides, most of these consumer devices are based on OEM hardware whose manufacturer usually writes the base firmware that the vendors then customize. The upshot is that even if your Linksys or SMC doesn't produce new firmware, the OEM manufacturer often does. My SMC 7004 Barricade is running firmware that provides considerably more functionality than SMC ever planned for the little box.
Re:Good, but not "plug and forget." (Score:2)
Re:Good, but not "plug and forget." (Score:3, Informative)
Re:Good, but not "plug and forget." (Score:2)
Re:Good, but not "plug and forget." (Score:2)
Re:Good, but not "plug and forget." (Score:2)
Re:Good, but not "plug and forget." (Score:3, Funny)
The answers you seek are probably not going to be found in A.B.P.E.*
Re:Good, but not "plug and forget." (Score:2)
They're embedded Linux boxes, and SnapGear provides all upgrades for free, so there's no catch with having to have a maintenence contract as with some others.
They seem pretty serious (much better than the average consumer gear, but not much more money), have a nice set of capablities, and are far more reasonably pric
Re:Good, but not "plug and forget." (Score:3)
Just running NAT without a DMZ or port mapping alone gives you the single biggest protection all by itself. Everything else is incremental improvement above that. But for most consumers that don't know sh!t about security, the best and simplest advice is to just get a simple NAT box. Especially since such consumers are most likely to merely browse and use email and would be perfectly served by NAT.
Re:Good, but not "plug and forget." (Score:2)
Re:Good, but not "plug and forget." (Score:2)
Re:Good, but not "plug and forget." (Score:3, Informative)
Re:Good, but not "plug and forget." (Score:3, Informative)
Not with Linksys, at least. The Firewall/NAT box I purchased four years ago (BEFSR11) is still being sold, and I still get firmware upgrades for it.
Re:Good, but not "plug and forget." (Score:2)
This isn't funny people, this is insightful. It really works and is good protection, under $50. If you don't have one, go get one. I recommend the BEFSR41 though because it has a built in 4 port 10/100 switch.
Good reasons to buy an Apple Airport (Score:4, Interesting)
hence apple airports are well worth the $50 premium you pay for them. The Apple software update will come with patches as needed for your security. You dont need to go looking, your apple will automatically get them the the moment they become available. You just have to run them. And you can be sure the apple updates will work well and not screw up your otherwise stable system. And the maintinence of the system is a freindly gui.
Re:Good, but not "plug and forget." (Score:3, Interesting)
Linksys will ask you to ship it back and offer a replacement in 3-4 weeks.
Re:Good, but not "plug and forget." (Score:2)
OP: Answer to your questions (Score:3, Informative)
Steve Gibson's site has a section to test all the ports associated with your network connection. Go there, scroll down and click on 'All Service Ports' - it will tell you if your system is vulnerable.
Behind a Linksys or SMC home router, you are invisible to the rest of the world. Not sure how much better it can get than that.
Re:Good, but not "plug and forget." (Score:2)
We had a bad D-Link D614+, wireless access point/router, and used the credit card to "pay" for the new one to a let them "immeadiately" ship the replacement, it still took 4 weeks to get the replacement. When we called to get a tracking number, the guy we talked to put us on hold while he walked to shipping to get the status; not what you'd expect from a company that specializes in computer networking!
The new router does work and has
Re:Good, but not "plug and forget." (Score:3, Insightful)
Jesus man, you are talking about a $60 piece of hardware. If your Internet connectivity is important to you, as in business grade connectivity important, just buy two and put one on the shelf. If your primary goes down go back to the parts closet and grab your spare, swap it out and you are back up and r
Re:Good, but not "plug and forget." (Score:2)
Correction. That should read "...If you buy the Cisco and are willing to pay for a support contract, then you'll never ever have to worry about finding someone to help you during downtime."
Cisco's products are not perfect. They do fail from time to time or have problems that may not necessarily qualify as a failure. All that the suppor
Re:Good, but not "plug and forget." (Score:2)
Hahaha! PIX is worse!
The only thing iptables/netfilter is missing is stateful failover. In every other way it is superior to the commercial firewall solutions. Unfortunately, this one missing feature makes it completely unsuitable for the most critical business applications.
um (Score:2, Informative)
Then your 'gurus' are dumbasses. Practially nothing gets past NAT. About the only thing that can compromise it is a trojan.
Your linux box is far more prone to hack attacks than an embedded device.
Re:um (Score:2, Informative)
Half of the current embedded devices are Linux boxes. :) The only difference is that most script kiddies don't know how to rewrite flash memory, so you can undo the eventual compromise with a power cycle.
Think of it as a little gateway box running Linux off CD, but without the ability to run intrusion detection software.
Re:um (Score:3, Informative)
You can create packets that a NAT will convieniently route to it translated LAN. We frequently see packets that are addressed to the 192.168.0.x range on the LAN. Really cool, especially given that folks seldom change the default address ranges. Kids, if you didn't know this, try it -- it's a good time!
NetGear ProSafe firewalls are the better bet as they are true stateful packet inspection firewalls. Of course, with great power comes great responsibility.
Firewall tips
Re:um (Score:2)
If so, then the 'security device' is broken - and has nothing to do with NAT.
Always block/log SSH, Telnet, FTP, TFTP, HTTP
Actually, you should block everything, except for stuff you know you need.
Use a non-standard IP address range for your LAN
Wrong - assume that anyone on the outside knows the IP address range you use for your LAN. Attempting to 'hide' this is security through obscurity - it does nothing to enhance yo
Re:um (Score:2)
Being allowed to ping your server is quite often convenient if you're having weird issues. Rather, you can restrict the addresses a PING is allowed from, or put in anti ping-flood rules (which is what I assume you are worried about).
If your firewall is a NAT type, run a software firewall on your desktops
The primary reason I love my NAT box is that ZoneAlarm and others also slow down my PC net connection, and cause other oddities.Having a proper NAT box means you shouldn't need anothe
Re:um (Score:2)
I wouldn't call them dumbasses, but they certainly haven't thought through it through.
Typically, NAT can be thought of as "poor-man's stateful packet filtering". That is, it provides a method for your security device to track inbound and outbound connections.
This is, of course, a very obvious security enhancement over standard packet filtering, and has nothing to do with obscurity.
Now, if (as another poster said) that the devices don't filter properly, then that's a sepa
morph (Score:5, Insightful)
Re:morph (Score:2)
It is true that OpenBSD systems may be more expensive in terms of TCO than a $50 home router, but only if your time has value. If you're a bored student with too much free time like me, you can get an OpenBSD router/firewall up and running literally for free, using old commodity hardware. I've used OpenBSD as a router on machines from a Pentium MMX 266MHz all the way down to a Pentium 60MHz, with no pro
Re:morph (Score:2, Insightful)
Or if you have to pay for electricity, or if space is limited.
The big question is whether the consumer router lets you do what you want/need with your network. The Linux/OpenBSD solution gives you the ability to do a lot of things that would otherwise require commercial grade equipment.
rubbish, my $10 linksys has all sorts of features (Score:2, Informative)
port triggering
dynamic routing
AOL parental controls
ftp://ftp.linksys.com/pub/manuals/befsru31_ug.p
Re:rubbish, my $10 linksys has all sorts of featur (Score:3, Funny)
It is very effective, in a Pavlovian sort of way.
Two things to remember (Score:5, Insightful)
2) Don't build a maginot line that a hacker can plow through and then discover that Paris has no more defenses. Good security is always a series of obstacles, as many obstacles that you can put in the way. Not one of them will be perfect, but enough obstacles that are sufficiently difficult will keep a hacker out. So use that Linksys router. And run a router on each box. And make sure that your subnet isn't routable or addressable from the outside. And make sure your external facing machines are firewalled from your internal network. And make sure that your patches are up to date. And scan your internal network often to make sure than no funny ports are open. And read the advisories. And run a virus scanner. And don't use Outlook for a mail client. And don't forget to use that nmap against your external network interface frequently; if that means getting an Earthlink account just for scanning your network from the outside then do it.
Re:Two things to remember (Score:2, Informative)
Re:Two things to remember (Score:2)
Re:Two things to remember (Score:2)
But when that moron down in dials up to AOL or his favorite ISP from his office machine, your defenses have just been breeched. His insecure windows system is now like a hooker waiting for the navy to come in. Every port open and ready.
So, yes, in addition to a strong firewall, be sure to regularly scan the internal network for problems.
Re:Two things to remember (Score:5, Funny)
So always wear pants while surfing the web -- don't let hackers get at your netherlands.
- Peter
IPCop (Score:5, Informative)
Re:IPCop (Score:2)
you can get OpenBSD for the same price?
Re:IPCop (Score:2)
Why IPCop instead of OpenBSD (Score:5, Informative)
1) if you're familiar with Linux it's easy
2) Great web/SSH interface esp. to snort output
3) Works really well
4) Quick and easy to install -very flexible about DMZ configs
5) Runs nicely on a box I'd need to upgrade (need +10GB HD) to put Astaro on it. (But I might do that at some point)
Re:IPCop (Score:2)
Re:IPCop (Score:2)
If my 7004BR wasn't so dam reliable(been running for years with barely any reboots) I'd replace it for anoth
Re:IPCop (Score:5, Informative)
When Compusa had a sale on those silver netgear routers, I grabbed one for ~$50. It sounded so simple, just plug it in, configure via web interface and you are done.
Then I tried to get it to work with SecuRemote VPN, and no luck. The box said in big, bold letters 'Supports VPN!'. So I dropped them an email and found they had shipped them without a VPN enabled firmware and I upgraded so it would work as advertised. The new firmware worked with my VPN client, but only one session at a time. Then it started hanging and not passing traffic every couple of hours. I'd have to reboot the thing several times a day. After reading on forums, I found the VPN firmware was buggy as all get out.
So I take it back and grab an SMC. This worked flawlessly, then started requiring a daily reboot after a couple of weeks usage. There were no firmware revisions to swap out, so I took it back to the store.
Since then, I hooked up my old P2 400 with IPCop and found it to be rock solid. It's been up for about 4 months without a reboot and, not once, have I had to trouble-shoot any problems with it.
If you get paranoid, Snort is there and simple to use via the web interface. I would definitely suggest this distro to anyone who's a Linux noob. You can download the ISO, burn it, pop it in, answer it's questions and have a very stable router running in about 30 minutes.
Yes, for security's sake OpenBSD would be a better choice, but this Linux distro will make setup much less painful. If you are concerned about security enough to point out the flaws of Linux and preach BSD, you don't need to be running this distribution anyway, as you are likely versed enough to set up your own BSD solution. In my case, I'm lazy and the ability to just grab security updates via a web interface fits my needs a bit better.
Re:IPCop (Score:2)
Re:IPCop (Score:2)
Hardware requirement (Score:2)
Ah, the days when you didn't need a heatsink the size of the eiffel tower and a fan capable of running a hovercraft... old machines do just fine for Routers/NAT and save power/noise/heat too.
Do you have the time? (Score:3, Insightful)
It all boils down to this, what you rather spend more of? Time or money? I use freebsd with natd/ipfw it's great for me, but I did it for the learning experience.
Depends on the application! (Score:3, Informative)
That being as it may, I was relatively inexperienced with ipTables, and honestly didn't know my ass from my forhead when it came to admin-ing. As such, I deployed one of the cheaper netgear firewalls; and to great success, I might add. Though it caused some isolated problems, it did its job and protected our network. Thus I can say I was happy with its performance.
As I've progressed in my techy career, I moved from such 'off-the-shelf' solutions, to building my own (extensive) iptables ruleset, to actually engineering my own 'blackbox' devices - these self-engineered devices were a product of my more ingenious years in college.
Well, this ramble can be summarized thus: "depends upon your application." Yes, Netgear et. al. produce a decent, well designed product. These solutions don't often attract much attention from the geek crowd due to their boilerplate nature, but they are function.
Now maintaining a rather massive network of thousands of people, I put my trust in a standalone, (sometimes) load-balanced front end consisting of an old x86 box running OpenBSD. The ruleset I carry with me is the product of several years of gradual modification, and is the best solution available (IMO).
Re:old x86 box, good idea! (Score:2)
OTOH, when a firewall box does finally die, you shouldn't lose much. The only thing of value on there was your config. And you did back that up, right?
Re:old x86 box, good idea! (Score:2)
Not only I did back it up: since the x86 box came for free I just configured two or three of them in the same way, so that when one fails I can replace it in no time.
Or at least this is what i'd do if I had a small network for something serious, and enough space.
If not secure, then more reliable (Score:3, Insightful)
Both FreeBSD and Linux have proven to be much more reliable against sometimes quirky network conditions. My current machine will have a new IP address and have updated my dyndns.org entries within 30 seconds of plugging in my DSL modem.
If you're going to get a firewall/router
appliance, get one that has something like Linux or BSD at its core.
Re:If not secure, then more reliable (Score:2)
NAT, meet Britney (Score:3, Insightful)
Think about this. If you did use ipchains, what would your first and most important rule be? My answer to that question is "deny all" (for a home network anyway). A side effect of NAT's inability to automatically map incoming connections is essentially a "deny all" rule. Because you probably need more than one IP address, you'll probably use NAT anyway. Therefore, you get this "deny all" rule for free. It, of course, doesn't hurt to use a linux-based firewall in addition to the NAT machine.
To sum it up, I wouldn't worry too much about it. It's not like anyone really wants your porn anyway
Re:NAT, meet Britney (Score:2)
And you weren't bothered at all by the extra traffic generated by CodeRed or slammer?
Network security is something that affects the entire network -- any compromized host is a bad thing. Worms can only work if there are vulnerable hosts waiting.
I don't worry about Grandma's port collection being compromised... I worry that Grandma's machine will be hijacked to send out worms and spam.
- Peter
Re:NAT, meet Britney (Score:2)
And again, how exactly is this a NAT vulnerability? After all, if you remember, that's what we're talking about here.
heh (Score:5, Interesting)
Which was the last I heard about it.
Basically, the gist of the problem was that outsiders on the internet were able to access SMB shares through the router on the internal network even though the ports were not forwarded. Even null routing those ports didn't work.
So, no, consumer NAT devices aren't really secure, but they are still an extra layer between you and "The world", which is nice if you run windows(I didn't need to worry about Blaster, or it's variants thanks to the linksys).
Re:heh (Score:4, Informative)
Linksys has an email address, security@linksys.com [mailto] set up so that you can report things like this. Tech support is for people who can't tell the LAN cable from the WAN cable, or need to be told to power-cycle their routers.
And if you don't hear anything back for a while after emailing them there, try posting it to Bugtraq [securityfocus.com] -- that'll get their attention, if nothing else.
Re:heh (Score:5, Funny)
"...people who can't tell the LAN cable from the WAN cable..."
The mental image I had on reading this was priceless - A dad sitting at home on the phone with a red RJ45 patch cable in one hand and a green RJ45 patch cable in the other.
Yeah, I know, it's early.
Re:heh (Score:2)
Is there anything I can do to minimise the chances that someone succeeds with such an attack? (settings changes, etc?)
Disable file sharing :)
Actually, you could probaly set windows to ignore requests from anything other than 192.168.* I imagine, though I'm better versed in *nix networking for that sort of thing.
Linux/Ipchains isn't very good either (Score:4, Insightful)
As for consumer NAT boxes? Well they're a lot harder to attack if they are done even half-baked. Coz NAT creates a fair number of barriers against inbound connections - an inbound packet needs to match an entry in the tables to go in to the right address/port pair behind. Unless there's a major screw up in the table matching bit, where is a packet going to go if there's no matching entry?
Maybe if they cut a few corners with DNS packets then the attacker could try sending spoofed DNS packets to trick people to go to a custom webmail site. Thing is, an attacker needing to have a site means leaving a bigger trail and the site can usually be shut down.
The usual holes in NAT are usually in handling NAT unfriendly protocols like FTP, H.323, IRC-DCC and so on. In fact if the box doesn't handle these its probably safer, so what if you lose a few features - Joe Schmoe doesn't even know about FTP, and really Joe Schmoe not being able to DCC files from someone (and stupidly run them) is a feature.
The other potential vulns are DoS - crashing the box - exploiting a box could be harder if it uses microprocessors which the attacker can't be bothered to get access to and figure out (most are script kiddies).
In all I think they are a good thing - such cheap firewalls significantly raise the barriers of entry to the masses.
Cheap and easy to use! (Score:5, Informative)
I never had any problems with off-the-shelf el-cheapo no-name home routers. I installed 4 such routers, 3 different brands in 3 companies and here at home. The latter one is a temporary solution, the other ones run for about 2 years now. No problems, except PPPoE related issues (MTU size limit and Linksys' inability to fragment them correctly, but this is an old Linksys). Even companies which wanted a more sophisticated router (Yamaha, Cisco) wanted: NAT, nothing incoming, everything outgoing. Not different from cheap home-routers.
That said, while a NATing router might not be the worlds securest solution, it's a very simple one and a pretty effective one too as long as users don't use the 'DMZ' feature, but I don't know anyone using it without knowing what it does in terms of attackability. For the money you pay, you get the ability to connect more than one computer to the Internet, and they are all no longer easily attackable. Great value for money.
Imagine a world where all users had those. Windows viruses/worms would have a much harder life to spread.
The key here is, that it's cheap and easy to use and it actually works. Compare that with a far more complicated Linux/*BSD firewall solution.
Re:Cheap and easy to use! (Score:3, Interesting)
It might seem strange that a cheap router could provide such high level of security. It's effective for the same reason that it's cheap: the technology is very simple. Machines on the local network can open connections to remote machines, but no remote machine can access a local machine. In fact, remote machines can't even address local machines -- the network IP addresses are meaningless outside the local network. This is f
My Experience (Score:4, Informative)
Linux (Redhat 6.1-ish?) firewall/occasional web and ftp server with a mix of Windows clients. The Linux machine was never compromised but it did begin crashing on a regular basis, I believe due to DoS attacks of an unknown form. I retired this box due to the crashes.
OpenBSD (3.0?) replaced this box with the same client load. No problems and no compromises, but keeping up with patches, particularly rebuilding the kernel, was a pain on such a slow machine.
Linksys box replaced that in the same environment. Again no compromises, but still no services really exposed. The lack of configurability compared to Linux/OpenBSD boxes was a pain.
Current setup of 3 static IP's, 2 with Linksys boxes protecting web/dns servers and 1 with a DLink WAP/NAT firewall box protecting client boxes. The servers (1 OpenBSD 3.3 and 1 Windows 2000) have had no compromises and the Linksys boxes have given me no problems at all. The DLink box is a pain because it apparently drops idle tcp connections after about 5 minutes. It's much more configurable than the Linksys boxes though. Still no compromises through the DLink firewall either.
So in short, I've never had a compromise through any firewall, hardware or unix-ish box. The only compromise I've had (except the DoS crashes on the Linux firewall) was a trojan from a downloaded piece of software.
It's another layer, and more layers is good (Score:5, Informative)
I have a routed block at home, and my basic setup is to use the embedded firewall (it's BSD running IPF as far as I can tell) to perform basic ingress/egress firewalling, DoS and portscan detection etc. and provide an Internet synched NTP server. All the firewall rule violations get sent back to a Linux box via SysLog and I also monitor network devices via SNMP. *All* my internal kit is restricted access by a local firewall; IPTables on the Linux boxes and Agnitum's excellent Outpost Pro [agnitum.com] on the Windows boxes. On top of all that, I have a slew of other stuff; TCPWrappers, a NAT'd wireless network locked down by MAC address, my switch is also locked to MACs and there is a small battery of IDS stuff running.
cheap test (Score:5, Informative)
And of course, for the Windows users, there's our free friend Zone Alarm [zonelabs.com] to help put another layer between your machine and the bad ol' Internet.
DT
Great advice. (Score:2)
Re:cheap test (Score:3, Informative)
NAT Issues (Score:2, Informative)
Re:NAT Issues (Score:3, Insightful)
I remember the noise about this, but I haven't seen any ISP's take notice or do
Re:NAT Issues (Score:2)
Cisco 675 (Score:2)
Cisco's products die. (Score:2)
Cisco's products have a curious quality: They die! [cisco.com] And you can't even read the death web page unless you pay Cisco money. This has been a VERY high total cost of ownership product. And now Cisco wants users to buy something else.
Why buy a product from a company that kills its products? Why buy a closed-source product? Frankly, I think there will come a time when there are no closed-source products.
I may not be able to defend myself now from aggressive business practices like those of Microsoft and C
Re:Cisco's products die. (Score:2, Interesting)
No, unfortunately, I don't have any links. This has been part of my problems as well.
However, from my experience, I can tell you this:
Netopia R910 (Score:3, Interesting)
Re:Netopia R910 (Score:2)
More is better (Score:2)
That said, I do have a Linksys packet filtering router that I use behind an OpenBSD packet filtering bridge.
It makes more sense to have my servers sitting behind the bridge, and my desktops behind the router. I think Zwicky et. al in Building Internet Firewalls call this a "screened subnet."
Having the packet filtering bridge operating on the outside edge of your network means that the number of people who have access to
NAT's stop outside connections in... (Score:4, Insightful)
So, turn on or add a firewall if you really are concerned. Not that that's a 100% solution either...
m0n0wall + embedded board = best of both worlds! (Score:2, Interesting)
Interesting, I just finished setting up this [m0n0.ch] on one of these [soekris.com].
I was pretty damn impressed with m0n0wall, it's freebsd-based and fits on an 8MB CF card, and has a nice web interface. Of course it's free software so you can hack it and improve it all you like (you need another FreeBSD box to do it on).
Check out this combo, it's the best of "play and play" and "high quality free software" in one Institutional Green sheet metal case!!
Effectiveness of consumer NAT/firewall boxes (Score:3, Informative)
I too have wondered if there were any exploits for consumer NAT/firewall boxes. Judging from posts so far, it would seem that at least there are none known :).
I started using the Linksys cable/routers when they first came out. I have insisted that all my neighbors, friends, and family with fast connections use a Linksys box (or similar).
There are a few points to bear in mind:
Observation (1) comes from running with both a Linux and Windows box exposed directly to the Internet. Both boxes had all unnecessary ports closed, were up-to-date on all patches, and carefully monitored. Neither machine was ever compromised. Periodic review of the logs showed a remarkable lack of intelligence on the part of the attacker. Practically all the activity was from a small number of popular crack-of-the-month scripts. Tracing the attacks back to their source - and getting the script kiddie kicked off their account - was seldom difficult.
So practically speaking, we don't have to worry about ultra-sophisticated attacks. The vast majority of script kiddies lack the needed intelligence.
Keep (2) in mind when you weigh the risk of failure. If a software firewall fails to run (for whatever reason) most likely your machine will be completely exposed. If the hardware NAT/firewall fails you will be safe (if without internet access). The software on your PC probably changes regularly. If any of those changes disables your firewall, the you might first notice when your machine is already subverted. The software in your NAT/firewall box never changes (discounting upgrades) so the chance of failure is less.Keep (3) in mind when evaluating effectiveness. Most folks with fast connections are not techies. A solution that works well and reliably for the bulk of the population is in the end far more effective.
Pride comes before the fall... (Score:3, Informative)
I remember feeling like this. Safe and secure behind my impenetrable shield of carefully tweaked and tuned software and hardware firewalls/NAT routers which was continually monitored and kept up to date. Sure in the knowledge that the only incidents I would have to deal with would be caused by office staff installing the "latest aquarium screensaver" and e
Re:Pride comes before the fall... (Score:2)
How do you know the people who are out to get you aren't TRYING to make you paranoid?
(Waits for brains to implode wrapping themselves around THAT one)
a linux firewall is easy too... (Score:2, Informative)
later,
ajay
PS. I'm not affiliated with them in anyway, blah blah blah...
Not really (Score:4, Interesting)
I know several people that have had problems using these. Not counting the problems with locking up by going for an URL on some (Linksys?), most people not bothering to change the default password and service providers or users or consultants turning on (or not turning off) the web management interface on the WAN side, these devices are designed to be used by people that have no business setting up and configuring firewalls.
I've seen them directly compromised where someone broke in, changed the password AND disabled the public interface. Additionally, people and frequently small businesses stick servers behind them, whether just forwarding a port or using the DMZ option. Great, leave an patched or unpatched Windows box accessible on every port sitting there fat dumb and happy for attack. And leave it on your LAN where it can be used to stage an attack on everything else on your LAN and everyone else in the world.
Of course I've also come across Cisco routers improperly configured to DMZ an Exchange server where every port except TCP 23 was forwarded and of course, it got owned.
My point is that these devices provide a very false sense of being immune to attack and an "army of know-it-all experts" ranging from jr. high schoolers to 60 something retirees that really have little or no knowledge. Somebody sets up four of these things and they are an expert. It's like reading the first paragraph of "War and Peace" and declaring yourself an expert on Russian literature.
Sometimes they are better than nothing, but they are worse than nothing when left in their default configuration or setup in a totally insecure way,leaving the "expert" confident that they are protected.
Maybe yes, maybe no. (Score:3, Informative)
The first issue is proper installation and configuration. Does the installer really know what they are doing and why? In many/most cases, the answer is no. The initial default configurations of these devices is usually very secure using a combination of NAT, which does indeed increase the level of security, and restrictive firewall rules. However, far too many people find the default configurations too restrictive for their needs and start opening holes in order to permit certain desired services like gaming. This is where the problems start. As unknowing installers open various ports or enable port forwarding or installing certain machines in "DMZ" zones the inadvertently open their systems up to the world.
The second issue is with the actual OS of the device itself. There have been a few vulnerabilities in the devices that you mention that allow for compromise of the actual firewall. I have personally found two Linksys devices that were compromised and reconfigured as open proxies for the purpose of relaying spam. The vulnerabilities were known and there were fixes available to resolve the issue but, people frequently do not know about these vulnerabilities and the firmware updates are not applied. In most cases they are never even aware that they have been compromised. Do you know how to determine if you have been compromised and how often do you check to make sure? So, regular maintenance is very important but very few ever check for, let alone install firmware updates.
The biggest issue is a true understanding of the risks and how to defend against them. I frequently see "qualified" network engineers with years of experience who still do not completely grasp the many facets of the IP protocol and how it can be used to invade a network. This does not however impact their belief that they are effectively installing and configuring firewalls of all varieties(shudder).
To answer your question directly, depending on the precise situation and the requirements of the network, a Linksys or Netgear firewall can be just as secure as a CheckPoint firewall but, all three must be configured correctly, monitored constantly and maintained regularly.
A thorough understanding of TCP/IP and its security is the most important step towards true security and this is in fact what most people lack. Look at this [slashdot.org] article asking about private IP addressing and the slew of comments that illustrate the person does not even understand subnetting. Yet, I'll wager that most of these people would not think twice about setting up a firewall and probably regard themselves as "experts" in network security.
The actual firewall is not as critical as the understanding of the firewall. Switching from Linksys to a Linux firewall isn't helpful if you don't truly understand what you are looking at with ipchains -Lvn or iptables -Lvn. In fact, if you don't truly understand the many facets of securing an IP network as well as hardening the Linux OS, you are far better off with the Linksys. At least, in the default configuration, it is more likely to be secure.
Its the same thing! (Score:3, Interesting)
Anyway the principal is the same in both cases. Both Linux and these devices offer you a firewall and both offer you NAT and a few other features. The NAT devices offer you ease of configuration and ease of use, while Linux, BSD, or any other UNIX type OS that has built in firewalling offers you a little more control over the firewalling. AFAIK you cant deal with frag packets in these NAT devices and specify various tcp flags or things. All they do is allow or deny various types of traffic. Also you cant set them up to do DNS / mail like you could a Linux / BSD system.
In the end it is a matter of preference IMHO and affordability. If you can afford one and don't want to deal with all the updates that you'd be applying to a Linux box or BSD system then that would be the way to go.
Re:Its the same thing! (Score:2)
In either case you have to keep them updated
Words of Warning (Score:3, Insightful)
It works great, never had a problem with it at all, but...
I have a linux server running on that network and traffic on port 22 is forwarded to the linux box. Add an old version of sshd and viola! Rooted.
Because I was behind that firewall though I didn't pay as much attention to the box as I should have and it took me a week to realize something was wrong.
Moral: The firewall can't protect you from yourself. You still have to be carefull behind it.
They're good, but... (Score:3, Informative)
A good firewall would mean setting up a Linux/BSD box, putting a couple NICs in it and setting it all up, right.
But 95% of the people who read a couple FAQs or books won't do it perfectly.
So the small appliances work great, as long as you can live with their limited functionality. If you just want 30 users to surf the web it'll be fine, but getting servers etc involved can be tricky with some models.
The worst thing is when they have poor security by default. We used to scan entire IP blocks, looking for open telnet ports, and we'd just use the default logins to get in. Anyone remember 'wradmin'?
You could telnet in, shut the DHCP off, or disable routing, telnet to other computers/printers inside their private networks, if it was an ISDN router you could change the dial out phone numbers...
Understand the risks? (Score:3, Interesting)
I hear people saying, well they run Linux, and Linux is hackable. With no ports open, how is it hackable? (DoS attacks don't count and neither do trojans running inside)
There's other choices... (Score:2)
Re:There's other choices... (Score:2)
BSD firewalls are very nice. Haven't popped OpenBSD on a box, yet, but I ran a firewall with FreeBSd before and it worked beautifully. While everyone else on our Adelphia network (about 2 years ago) was getting scanned and attacked, we were sitting pretty. Worked right up until the machine got fried in a lightning strike.
Of course, I'm now looking into my next setup, which'll like have my OpenBSD box (installing in the next couple weeks) and then a firewall, followed by another firewall, and then my other
Re:There's other choices... (Score:2)
Funnily enough.. (Score:5, Funny)
Re:Funnily enough.. (Score:2)
Assuming your story is true, which, frankly, I doubt.
Reasonably secure -- but watch out for UPNP (Score:2, Informative)
But a lot of them support "UPNP", which allows programs on the to automatically open up ports they need. This is a great convenience, but you're now giving the keys to your network to any random Windows program. Now any trojans don't need to actively call out -- they can just open up your firewall FOR you and wait for connections. This strikes me as
OT: Request for firewall help (Score:2)
The question I have is this: I have some ports open from the outside, for specific purposes (ssh, for example). Now if I'm going to have ports open, what do I need to have blocked to avoid spoofing?
For instance, I currently am blocking incoming traffic:
1) with a source IP of 127.x.x.x
2) with a source IP from inside my firewall
3) with any other non-routable source IP
What else do I need to block, before forwarding it on to the appropriate machine/
Forget routers, how about hubs? (Score:2)
Shouldn't meaning that any machine I plug (3 different OS's) into the switch and it starts a blazing trail of packets. Plug it into itself (normal port into uplink port) and it blazes away too. A reboot fixes it.
I haven't figured out the cause yet, or why... but it often seems to start with a lot of data passing through