Earlier this week, researchers published information about a newly discovered weakness in the security standard that protects all modern Wi-Fi networks we use at home, work, restaurants, etc. We want to inform you what is at stake here, who is most at-risk, and what organizations and individuals can do about it.

What is the ‘KRACK’ Wi-Fi Security Weakness?

WPA2, or Wi-Fi Protected Access II, is the security standard used by most wireless networks today. Researchers this week have discovered and published a vulnerability in WPA2 that allows anyone to bypass this security wall and steal data flowing between your wireless device(s) and the targeted Wi-Fi network, such as passwords, chat messages, photos, and possibly more.

“The attack works against all modern protected Wi-Fi networks,” the researchers wrote of their discovery dubbed KRACK, short for “Key Reinstallation AttaCK.”

“Depending on the network configuration, it is also possible to inject and manipulate data,” the researchers continued. “For example, an attacker might be able to inject ransomware or other malware into websites. The weaknesses are in the Wi-Fi standard itself, and not in individual products or implementations. Therefore, any correct implementation of WPA2 is likely affected.”

This means the vulnerability can potentially impact different types of devices including those running on Android, Apple, Linux, and Windows operating systems.

How To Protect Yourself From ‘KRACK’ WPA2 Security Weakness

Attacker Can Only Be Within WiFi Range
First of all, an attacker can only be within the range of the wireless signal between your device and a nearby wireless access point.

Safety Tip: Unless you need it on, disconnect your Wi-Fi router before going to bed. This will disconnect your devices from the outside world and keep away any intrusions.

You’re SSL Protected
Most sensitive communications, such as correspondence with financial institutions, are likely already protected end-to-end with SSL encryption that is separate from any encryption provided by WPA2. You would notice if a website was using SSL by seeing https:// in the beginning of the URL.

Update Your Software With Patches
Major platform providers have already started deploying patches to their Wi-Fi users.

Mac Users: Since this attack compromises the WPA2 protocol that both your wireless devices and wireless access point (ie routers) use, MAC filtering is not a particularly effective deterrent against this attack. Nevertheless, MAC addresses can be spoofed fairly easily.

The recent versions of Windows and Apple’s iOS are likely either not vulnerable to this flaw or are only exposed in very specific circumstances. Android devices, however, are more at risk and will need patching soon.

Check the CERT advisory if there update available for your computer, wireless device or access point. If so, read and understand the instructions on updating those devices before you update. Failing to update properly can quickly leave you with a broken piece of equipment.

Here is the original publication (PDF) released by the researchers who discovered the bug.