As you are already aware a serious vulnerability in the WPA2 encryption protocol was publicly disclosed Monday. Most devices and routers currently rely on WPA2 to encrypt your WiFi traffic, so chances are you’re affected. The weakness in the security can be exploited using key reinstallation attacks, hence the nickname “Krack attack.”
But first, let’s clarify what an attacker can and cannot do using the KRACKvulnerability. The attacker can intercept some of the traffic between your device and your router. If traffic is encrypted properly using HTTPS, an attacker can’t look at this traffic. Attackers can’t obtain your Wi-Fi password using this vulnerability. They can just look at your unencrypted traffic if they know what they’re doing. The attacker needs to be in range of your WiFi network. They can’t attack you from miles and miles away.
We are strongly advising you to review all your WiFi devices and update all systems with the latest updates/firmware
Here’s in detail what to do now that the WPA2 protocol is vulnerable
Update all the wireless things you own
You should update all your routers and Wi-Fi devices (laptops, phones, tablets…) with the latest security patches. You can also consider turning on auto-updates for future vulnerabilities as this won’t be the last one. Modern operating systems have become quite good at auto-updates. Some devices (ahem Android) don’t receive a lot of updates and could continue to pose risks.
Your router’s firmware absolutely needs updating. If the router has been supplied by your ISP, ask the company when their branded kit will be patched. If they don’t have an answer, keep asking. You can make sure your router is up-to-date by browsing the administration panel. Find the user guide for your ISP-branded router and follow the instructions to connect to the admin pages.
If your router doesn’t yet have a fix, and you don’t have a patched WiFi access point that could be used for wireless instead, you could use an Ethernet cable to connect to your router and turn off its wireless function until it’s patched (assuming WiFi can be disabled on your router). Turn off WiFi on your device as well so that you’re sure all traffic goes through that sweet Ethernet cable.
If you still want to keep WiFi for some devices, consider switching to Ethernet for your essential devices. For instance, if you spend hours every day on a computer and use a ton of internet traffic from this computer, buy an Ethernet cable.
Consider using cellular data on your phone
Your phones and tablets don’t have an Ethernet port. If you want to make sure nobody is watching your traffic, disable WiFi on your device and use cellular data instead. This isn’t ideal if you live somewhere with a spotty network, pay extra for mobile data, or if you don’t trust your telecom provider.
Devices running Android 6.0 and later are more vulnerable than other devices. It is trivially easy to perform a key reinstallation attack because of a bad implementation of the handshake mechanism in the WiFi stack. Therefore, Android users do need to be more careful.
What about Internet-of-Things devices?
If you own a lot of IoT devices, consider which of those devices pose the most serious risk if unencrypted traffic is intercepted. Say, for example, you own a connected security camera that doesn’t encrypt traffic when you’re on the same WiFi network — well, that could allow attackers to snoop on raw video footage inside your home. Erk!
Take action accordingly — e.g. by pulling the most risky devices off your network until their makers issue patches. And be sure to keep an eye on the kinds of devices your kids might be connecting to your home network.
At the same time, if an attacker can intercept traffic between your smart lightbulbs and your router, it’s probably fine. What are they going to do with this information anyway? It’s fair to say that Edward Snowden wouldn’t want even info about how his lightbulbs are being turned on and off getting into the hands of a hacker, and with good reason. But most people aren’t at risk of such an extreme level of state-sponsored surveillance. So you should determine your own level of risk and act accordingly.
Install the HTTPS Everywhere extension
As mentioned above, you can mitigate risks by prioritizing encrypted internet traffic over unencrypted traffic. The EFF has released a neat browser extension called HTTPS Everywhere. If you’re using Google Chrome, Firefox or Opera, you should consider installing the extension. There’s no need to configure it, so anybody can do it.
If a website offers unencrypted access (HTTP) and encrypted access (HTTPS), the extension automatically tells your browser to use the HTTPS version to encrypt your traffic. If a website still relies exclusively on HTTP, the extension can’t do anything about it. The extension is no use if a company has a poor implementation of HTTPS and your traffic isn’t really encrypted. But HTTPS Everywhere is better than nothing.
When you use a public VPN service, you reroute all your internet traffic to a VPN server in a data center somewhere. An attacker can’t see what you’re doing on your WiFi network, but a VPN company can log all your internet traffic and use it against you.
Especially paranoid? Move to the woods…
For the most paranoid out there, who don’t want to/can’t stop using WiFi entirely, it may be time to relocate to a remote cabin in the woods far from any neighbors/wardrivers.