A new set of vulnerabilities known as Frag attacks have been discovered in Wi-Fi-enabled devices. Some of these issues date back to the original Wi-Fi standard that was first established in 1997.

So, how do Frag attacks happen? Which devices are most vulnerable? And how can you protect against them?

What Are Frag Attacks?

Belgian academic and security researcher Mathy Vanhoef discovered twelve different vulnerabilities in Wi-Fi devices which have the potential to turn into security issues. These are better known as Frag attacks.

A Frag attack does one of the two things:

  1. It captures traffic passing through unsecured networks, mimics it, and then impersonates servers.
  2. It injects the network traffic with malicious plaintext frames that resemble handshake messages.

To put it simply, the Frag attacks dupe your Wi-Fi-connected devices into thinking they are conducting safe business.

Which Wi-Fi Flaws Are Responsible for Frag Attacks?

During the discovery of Wi-Fi vulnerabilities, it was concluded that three of the issues pertained to design flaws within the Wi-Fi protocol, while the rest were programming mistakes.

The biggest downside to these vulnerabilities is that they make it possible to access even fully secure Wi-Fi networks with WPA2 or WPA3 encryption in place.

One major vulnerability was found in the fragmentation process which is an integral feature of a Wi-Fi network used for improving performance degradation for excessive background noise. By splitting data into manageable fragments or "chunks" for transmission, they can be reassembled with ease when received.

Unfortunately, Vanhoef discovered security weaknesses in the process. He said:

“You can cause a receiver to reassemble two fragments that belong to different packets or even store malicious data and combine it with legitimate information. Under the right conditions, this can be used to exfiltrate data.”

Also, in certain cases, attackers can inject malicious packets of data through a router's firewall if a connected device is vulnerable. This allows the hackers to unmask IP addresses and destination ports used to access the device.

Which Devices Are Most Vulnerable to Frag Attacks?

Unfortunately, every Wi-Fi device to date is vulnerable to Frag attacks as the discovered vulnerabilities go back to 1997 when the Wi-Fi base standard was first released.

The good news is that the vulnerability was not revealed to the public until nine months after its discovery. This gave most companies ample time to release security patches and update their devices against these attacks.

In its attempt to protect Windows against the Frag attacks, Microsoft published an update on March 9, 2021.

Main Risk Factors for Frag Attacks

Worried about falling prey to potential Frag attacks? Then you should know about the two main risk factors for these attacks.

1. Data Theft

A Frag attack can be used by an attacker to steal and intercept data from a Wi-Fi network. Most websites and applications that employ HTTPS and other types of encryption are protected against such attacks.

However, if unencrypted data is sent over an encrypted Wi-Fi connection, a Frag attack can potentially bypass the encryption and cause data theft.

Related: Does HTTPS Protect Data in Transit?

2. Attacks Against Vulnerable Devices

Most smart home and IoT devices can be vulnerable to a Wi-Fi Frag attack. Smart devices manufactured by unknown brands such as an inexpensive smart plug or smart light bulbs might not offer the necessary long-term support and updates, causing these devices to easily fall victim to Frag attacks.

In reality, it should not matter because every device, whether big or small, is connected to a trusted home network. But since Frag attacks can bypass a Wi-Fi network's encryption, any device can be targeted directly just as if it was connected to the same network.

Should You Be Worried About Frag Attacks?

If you own a device that is connected to a Wi-Fi network, then you should be concerned even though no known cases of Frag attacks have been documented yet. The mere fact that the vulnerabilities were discovered in the Wi-Fi design poses a risk for a potential attack at all times.

Also, there are certain factors that make you more or less vulnerable to these attacks.

Shared Radio Range

You are at a higher risk of a Frag attack if the attacker is in the same physical vicinity or radio range of your Wi-Fi network.

Densely Populated Locations

densely populated area

If your Wi-Fi device is located in a densely populated area like apartment buildings or tall skyscrapers, you are at a higher risk of a Frag attack. Your risk factor for an attack reduces the more physically isolated you are.

Corporate Networks

Corporate networks and Government institutions can be prime targets and are always at a greater risk for Frag attacks compared to an average home-based Wi-Fi user.

How to Protect Against Frag Attacks

Thankfully, there are quite a few ways to keep your devices protected against potential Frag attacks. Most of which are standard security best practices that protect against other cyberattacks as well.

Keep Up-to-Date With Security Updates

Always ensure that your devices are running the most recent security updates. Most modern devices automatically install updates for you but for certain devices like routers, you might still need to manually select an option or click a button to accept the installation.

Update or Replace Obsolete Devices

Like anything in life, our devices and applications also require upgrades and replacements. If you are still using a Windows 7 PC or an older version of macOS that is not receiving updates anymore then it is better to invest in an upgrade instead of taking a risk.

The same holds true for obsolete devices like routers or smart plugs that are not receiving firmware upgrades from the manufacturers anymore. Most obsolete devices will likely have security flaws and should be replaced with newer models.

Use Secure Encryption

HTTP vs. HTTPS
Image Credit: Shutterstock.

Most browsers like Google Chrome have transitioned to HTTPS—the secure version of the internet protocol or HTTP—due to the encryption capabilities it offers. Every time you access a website, make sure you are on an HTTPS site.

Better yet, installing a browser extension like HTTPS Everywhere is helpful.

You can also configure your browsers such as Firefox to warn you before loading websites that are not encrypted. Here is how you can do that:

  • On the Options tab of your browser, click Privacy and Security in the sidebar.
  • Select the Enable HTTPS-Only Mode in all windows option.

Always remember to use encryption even if you are simply transferring files between devices on your local network. This can be done by using an application that offers encryption for secure transfers.

Patch Security Loopholes and Stay Safe from Frag Attacks

Frag attacks have not been exploited yet and only the vulnerabilities in Wi-Fi devices have been discovered so far. But this does not guarantee that your Wi-Fi devices won't become a victim of a real Frag attack one day.

The only way to avoid any future Frag attacks or any security attacks is to patch away all your security loopholes. This can be easily achieved by ensuring all your Wi-Fi-connected devices are up-to-date, upgraded, and fully encrypted.