Firewall limitations (and what to do about them)

It’s true, firewalls can’t do everything. Corporate Armor provides a lot of firewalls to our customers, like the Fortinet FG-40F, FG-80F, and FG-100F, as well as Sophos’ XG115, Meraki MX64 and MX100, SonicWall TZ400 and so on. And it would be easy to believe that buying a good firewall is enough to protect your IT infrastructure. However, that’s not always the case.

A hardware firewall acts as a gateway to the internet. It provides access to the internet, and filters and logs all traffic that comes through it based on rules that you set for it.

The fact is, there are certain things traditional firewalls aren’t that good at. Over time, the kind of threats facing your network has expanded greatly. So, too, has their sophistication. The introduction of all-around Next-Gen firewalls has addressed this fact. These are Jacks-of-all-trades that do an admirable job for many organizations.


…firewalls have certain limitations. A firewall is used in critical points of the network. Chokepoints, basically. And their misconfiguration can have disastrous consequences. Firewalls are often a single point-of-failure within a network. One mistake in either configuration or firewall code can compromise the network access policy. It’s a good reason to have additional measures of security besides just a Next-Gen firewall.

For another thing, many of the modern applications are firewall-unfriendly. That’s because they are difficult to inspect properly. Subsequently, compromises in rule design and inspection depth have to be made to support such applications.

Inside jobs

Also, a firewall cannot reliably protect your network when users do the hacker’s job for them. An example would be social engineering. This is where someone reveals login details or personal information to an unauthorized source. For example, by clicking a link in an email or going to fake version of a site they use. Firewalls are pretty sophisticated and some will warn a user if something doesn’t look quite right. But the problem is one of user awareness. It’s better to educate people on internet safety than completely rely on the technology.

Another example of this is when users behind the firewall move unauthorized data over authorized connections. This is simple and generally impossible to detect. Such activity usually requires the help of someone on the trusted side of the firewall.

And firewall restrictions can cause users to go around the firewall, on purpose. If strict policies result in heavy backdoor use by employees, attention may be called to these unprotected entry points and exploited.

Also, firewalls only serve as a wall to block unauthorized data transmissions They don’t provide anti-virus or anti-spyware capabilities. So you’ll need additional protection if this harmful software is accidentally introduced into the system through trusted channels like email. Not only that, firewalls also draw considerable attention from would-be intruders. They become a focal point of attacks. Should an attempted breakthrough prove successful, your company’s network is completely at the mercy of the intruder.


Even though a firewall can block the basic trojans, they are less successful against other types of malware. These can enter your system in the form of trusted data. So even if you have a firewall, it’s still wise have an anti-malware software installed on your PC.

A firewall is one of the most effective tools of network access control. They will continue to be used as networks and applications become more and more complex. They augment network security by hiding potentially vulnerable services. And, they permit only the minimum allowed access, inspecting connections, protocols and applications. However, firewalls should never be the only line of defense against a modern attacker. Their limitations must be understood.

Of course, Corporate Armor is ready to field your questions more in-depth. And we have a full selection of IT security answers for any questions you may have. And that includes firewalls. So why not email us, or call 877-449-0458 and let our experts steer you in the right direction? Thanks for reading!

What does a firewall protect against?

Malware such as viruses, ransomware and trojans
Bots and other automated software
Hacks and intrusions
Encrypted threats
Malicious apps and websites