Fundamentals of Security: How Solid are Firewalls?

In our security series, we introduce common concepts in device security. The last item in our series was an introduction to SSH . In this segment, we discuss firewall security, setup, and maintenance.

Firewalls are a critical component of keeping machines and networks safe. You’ll find them on everything from your laptop to your router. They require maintenance, like any software program, and unfortunately there are problems that interfere with their ability to keep attackers safe.

Firewalls are typically software that is written, configured, and maintained by people. People who can, and do, make mistakes.

While software is still written by people, it will continue to have bugs. Firewalls too can have bugs that prevent them from keeping intruders out and protecting the computers and networks they are installed on.

Firewalls operate with lists that allow or deny certain ports, ip addresses, and traffic. A firewall could be working perfectly, but unless it has been properly configured, it could still be letting attackers in.

Like all software, firewalls need to be maintained by installing patches and updates. If these patches are not installed, then the firewall cannot do its job correctly, and the network may be left open to attack.

It's important to keep in mind that, while firewalls are important, one security solution cannot be solely responsible for keeping intruders out. Make attackers eat the whole onion , and layer your defenses.

Come back soon for the next item in our series. Or check out our work on lateral attacks to find out what happens after an intruder accesses network equipment.