KRACK Wi-Fi attack threatens all networks: How to stay safe and what you need to know
Table of Contents
- 1 How does KRACK break Wi-Fi security?
- 2 What devices are affected by KRACK?
- 3 What happens when Wi-Fi security is broken?
- 4 Is Wi-Fi security being broken in the wild?
- 5 How to protect yourself from KRACKâs Wi-Fi flaw
- 6 Device and router Wi-Fi security FAQ
- 6.0.1 Is my phone at risk?
- 6.0.2 So my router is vulnerable?
- 6.0.3 Oh, so I should change my Wi-Fi password then?
- 6.0.4 So all devices are at risk?
- 6.0.5 Great, I have an Android phone. But Iâm running Nougat so Iâm safe, right?
- 6.0.6 So are my iPhone and Mac safe?
- 6.0.7 And Windows PCs too?
- 6.0.8 I run Linux. Iâm impenetrable to attack, right?
- 6.0.9 So should I turn off Wi-Fi?
- 6.0.10 OK, Iâm not doing that. What else can I do?
- 6.0.11 I have automatic updates turned on. How do I know if my device has been updated?
- 6.0.12 What about my router?
- 6.0.13 Related
A devastating flaw in Wi-Fiâs WPA security protocol makes it possible for attackers to eavesdrop on your data when you connect to Wi-Fi. Dubbed KRACK, the issue affects the Wi-Fi protocol itselfânot specific products or implementationsâand âworks against all modern protected Wi-Fi networks,â according to Mathy Vanhoef, the researcher that discovered it. That means that if your device uses Wi-Fi, KRACK likely impacts it.
Read on for what you need to know about the KRACK Wi-Fi vulnerability, from how it works to how to best protect yourself against it. Weâll update this article as more information becomes available.
How does KRACK break Wi-Fi security?
KRACK (short for, uh, Key Reinstallation AttaCK) targets the third step in a four-way authentication âhandshakeâ performed when your Wi-Fi client device attempts to connect to a protected Wi-Fi network. The encryption key can be resent multiple times during step three, and if attackers collect and replay those retransmissions in particular ways, Wi-Fi security encryption can be broken.
Thatâs the CliffsNotes version. For a more technically detailed explanation, check out Mathy Vanhoefâs KRACK attacks website.
What devices are affected by KRACK?
If your device uses Wi-Fi, itâs likely vulnerable to the KRACK Wi-Fi security flaw to some degree, though some get it worse than others. We go into greater detail about how particular devices are affected by KRACK in a dedicated section further below.
What happens when Wi-Fi security is broken?
For starters, the attacker can eavesdrop on all traffic you send over the network. âThis can be abused to steal sensitive information such as credit card numbers, passwords, chat messages, emails, photos, and so on,â Vanhoef says. For a deeper look at the potential impact, check out PCWorldâs article on what an eavesdropper sees when you use an unsecured Wi-Fi hotspot. Itâs a few years old, but still illuminating.
The United States Computer Emergency Readiness Team also issued this warning as part of its KRACK security advisory, per Ars Technica: âThe impact of exploiting these vulnerabilities includes decryption, packet replay, TCP connection hijacking, HTTP content injection, and others.â HTTP content injection means the attacker could sneak code into the websites youâre looking at to infect your PC with ransomware or malware.
So yeah, itâs bad. Keep your security software active, just in case.
Is Wi-Fi security being broken in the wild?
âWe are not in a position to determine if this vulnerability has been (or is being) actively exploited in the wild,â Vanhoef says. US-CERTâs advisory didnât include any information about whether KRACK is being exploited in the wild, either.
Now for some somewhat settling news: Iron Group CTO Alex Hudson says an attacker needs to be on the same Wi-Fi network as you in order to carry out any nefarious plans with KRACK. âYouâre not suddenly vulnerable to everyone on the internet,â he says.
How to protect yourself from KRACKâs Wi-Fi flaw
Keep your devices up to date! Vanhoef says âimplementations can be patched in a backwards-compatible manner.â That means that your device can download an update that protects against KRACK and still communicate with unpatched hardware while being protected from the security flaw. Given the potential reach of KRACK, expect those patches to come quickly from major hardware and operating system vendors.
Update: Microsoft told Windows Central that a patch quietly rolled out on October 10 protects Windows 10 PCs against KRACK.
âMicrosoft released security updates on October 10th and customers who have Windows Update enabled and applied the security updates, are protected automatically. We updated to protect customers as soon as possible, but as a responsible industry partner, we withheld disclosure until other vendors could develop and release updatesâ
Until those updates appear for other devices, consumers can still take steps to safeguard against KRACK. The easiest thing would be to simply use a wired ethernet connection, or stick to your cellular connection on a phone. Thatâs not always possible though.
If you need to use a public Wi-Fi hotspotâeven one thatâs password protectedâstick to websites that use HTTPS encryption. Secure websites are still secure even with Wi-Fi security broken. The URLs of encrypted websites will start with âHTTPS,â while unsecured websites are prefaced by âHTTP.â The Electronic Frontier Foundationâs superb HTTPS Everywhere browser plug-in can force all sites that offer HTTPS encryption to use that protection.
Alternatively, you can hop on a virtual private network (VPN) to hide all of your network traffic. Donât trust random free VPNs, thoughâthey could be after your data as well. PCWorldâs guide to the best VPN services can help you pick out a trustworthy provider. And again, keep your security software up to date to protect against potential code injected malware.
Device and router Wi-Fi security FAQ
Is my phone at risk?
KRACK is a different sort of attack than previous exploits, in that it doesnât go after devices, it goes after the information you use them to send. So while the data stored on your phone is safe from hacking, whenever you use it to send a credit card number, password, email, or message over Wi-Fi, that data could be stolen.
So my router is vulnerable?
Thatâs closer, but still not totally accurate. Itâs not the device thatâs at risk, itâs the information, so the sites you visit that arenât HTTPS are most vulnerable.
Oh, so I should change my Wi-Fi password then?
Well, you can, but itâs not going to stop the likelihood of attack. The exploit targets information that should have been encrypted by your router, so the attacker doesnât need to crack your password to implement it. In fact, it has no bearing on the attack whatsoever.
So all devices are at risk?
Now youâre getting it. However, while any device that sends and receives data over Wi-Fi is at risk, the researchers who uncovered the attack said Android devices were more at risk than other mobile phones.
Great, I have an Android phone. But Iâm running Nougat so Iâm safe, right?
Unfortunately, no. Newer phones running Android 6.0 or later are actually more at risk since there is an existing vulnerability in the code that compounds the issue and makes it easier to âintercept and manipulate traffic.â
So are my iPhone and Mac safe?
Safer than Android, but still not entirely safe. Update: Apple said in a statement that all current iOS, macOS, watchOS, and tvOS betas include a fix for KRACK.
And Windows PCs too?
Yup, same deal, but Microsoft said in a statement that it has a security update to address this issue incoming. Update: Nope. Microsoft released a patch to protect against KRACK on October 10, before the vulnerability was made public.
I run Linux. Iâm impenetrable to attack, right?
Not quite. Researchers actually found that Linux machines were the most vulnerable desktop devices, with a similar bug to the one found in the Android code.
So should I turn off Wi-Fi?
Thatâs probably not a viable option for most people, but if youâre completely panic-stricken, then the only way to be completely safe is to avoid using Wi-Fi until you know your router has been patched.
OK, Iâm not doing that. What else can I do?
Right now, all you can do is wait. Google has already confirmed that it is aware of the issue and will be distributing a patch, and Apple and Microsoft will presumably do the same, as well as Linux purveyors. So keep checking for updates and install them when they arrive.
I have automatic updates turned on. How do I know if my device has been updated?
The quickest way is to check the system our software updates tab in your Settings app to see when the most recent version has been updated. Also, Owen Williams is keeping a running list of companies that have distributed patches on his Recharged blog.
What about my router?
First, you should check to see if your router has any pending firmware updates. Most people arenât as vigilant in updating their routers as they are with their phones or PCs, so log into your admin page and install any waiting updates. If there arenât any, itâs a good habit to check back every day, since companies will be rolling out patches over the coming weeks, with some already being implemented.