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Ask Slashdot: Is Running Mission-Critical Servers Without a Firewall Common?
An anonymous reader writes: I do some contract work on the side, and am helping a client set up a new point-of-sale system. For the time being, it's pretty simple: selling products, keeping track of employee time, managing inventory and the like. However, it requires a small network because there are two clients, and one of the clients feeds off of a small SQL Express database from the first. During the setup, the vendor disabled the local firewall, and in a number of emails back and forth since (with me getting more and more aggravated) they went from suggesting that there's no need for a firewall, to outright telling me that's just how they do it and the contract dictates that's how we need to run it. This isn't a tremendous deal today, but with how things are going, odds are there will be e-Commerce worked into it, and probably credit card transactions... which worries the bejesus out of me.
So my question to the Slashdot masses: is this common? In my admittedly limited networking experience, it's been drilled into my head fairly well that not running a firewall is lazy (if not simply negligent), and to open the appropriate ports and call it a day. However, I've seen forum posts here and there with people admitting they run their clients without firewalls, believing that the firewall on their incoming internet connection is good enough, and that their client security will pick up the pieces. I'm curious how many real professionals do this, or if the forum posts I'm seeing (along with the vendor in question) are just a bunch of clowns.
So my question to the Slashdot masses: is this common? In my admittedly limited networking experience, it's been drilled into my head fairly well that not running a firewall is lazy (if not simply negligent), and to open the appropriate ports and call it a day. However, I've seen forum posts here and there with people admitting they run their clients without firewalls, believing that the firewall on their incoming internet connection is good enough, and that their client security will pick up the pieces. I'm curious how many real professionals do this, or if the forum posts I'm seeing (along with the vendor in question) are just a bunch of clowns.
Or bandwidth. Or visitors. Or intern-connections. There's a lot of room for serious damage from a lack of security, and not all of it is data theft.
People using your server as a spambot is bad.
People infecting your sites visitors with malware is bad.
People jumping to a different, more secure system from your server is bad.
We tend to notice the data theft issues most these days, because a lot of companies keep a lot of sensitive data, so a Target credit card hijack is tremendously bad and newsworthy.
But that doesn't mean other classes of security risk don't exist.
It sounds like you're some bureaucrat trying to justify the costs of standard security practices.
The objective of any firewall is to prevent traffic on all unused ports in order to limit potential attack vectors. This is a given and no specific threat needs to be stated.
Put the firewall up FIRST, and open essential ports as necessary. This is network security 101.
Depends on the quality of the web apps running under LAMP
If they get hacked, it may be possible for the attacker to spawn a new process running on some other port (ie, a shell), or sending stuff out to other machines, so having a firewall that only allows the services you have listening may be good, as well as possibly having it restrict new outgoing connections.
And no, you don't need to write complicated iptables scripts/rules to do this. The ufw utility (available in Debian, Ubuntu, Mint, etc) has truly simple syntax
ufw allow ssh
ufw allow http
ufw allow https
ufw enable
Don't blame me, I voted for Kodos
Exactly. Too many people (both businesses and home users) say "Well, I don't have anything that 'those hackers' would want so why bother with protections?" The thing is, though, you DO have something they want. At the very least, a home user has bandwidth. If a malware author hijacks a computer, he can use it to pump out tons of spam. The user might notice an annoying slowdown but otherwise wouldn't know what was up. In the case of businesses, infecting your customers with malware (due to being hacked) or your site slowing down to a crawl (because it is a spam bot and is spending precious resources spamming people) is a sure method to lose customers. I'd wager that the money "gained" by not doing a proper firewall network is more than lost by the "lost sales" of customers fleeing after the servers have been hacked.
My sci-fi novel, Ghost Thief, is now available from Amazon.com.
It doesn't matter if it's a rational argument backed up by facts or not, or if he's done a risk assessment, or if it's a free, cheap, or expensive firewall. The Payment Card Industry's Data Security Standard (PCI DSS) has as their very first requirement 1: "Install and maintain a firewall configuration to protect cardholder data." It's not an optional requirement, and you can't justify not having one.
If you're going to handle credit cards on the system, it has to be protected with a firewall.
If your POS vendor isn't requiring a firewall, either they are not selling a system that takes credit cards, or they are selling shoddy, insecure systems that are in violation of PCI DSS. Fixing these problems will cost you dearly; worst case, they are setting you up for a breach.
John