KRACK: Vulnerability in WPA2 protocol (WLAN security hole)

KRACK is the name of a current WLAN security gap that results from a vulnerability in the WPA2 protocol. The abbreviation stands for Wi-Fi Protected Access 2 and thus actually for a security standard in Wifi networks of the standards IEEE 802.11a, b, g, n and ac. However, an update of this security protocol now seems to be necessary - because a KRACK attack, according to many sources, can be done by every single WLAN Device. In this post I would like to explain the topic a little more.

All routers affected by the KRACK vulnerability

The risk is independent of the WLAN router used or the device that is dialed into the corresponding wireless network. The security gap is in the WPA2 security standard, which is used around the world and pretty much everywhere. This is actually used for encryption, but can be attacked and used as access to the individual devices. The dangers here are espionage, the placement of malware by attackers and the like.

What can happen to me as a user in the event of an attack?

As mentioned, attackers could use malware (viruses, Trojans, Ransomware, etc.) on the device used. Passwords, emails, chat messages, photos and other files, and credit card numbers can also be stolen. However, and this is the positive side, end-to-end encrypted data paths are safe. This means that, for example, the Google password or the bank details cannot be read out per se in online banking. If you use a network printer via WLAN, unwanted printouts could appear - depending on how creative the hackers are.

Laut Spiegel Online Linus Neumann, spokesman for the Chaos Computer Club (CCC) said the following about KRACK and online banking:

"I am not aware of any online banking provider where this attack method would be successful."- However, the addition:"If, for example, a certificate warning pops up, you should definitely not simply click it away - especially not when doing online banking."

What's the solution to the problem?

The solution consists of updates from device manufacturers. Not (only) the manufacturers of routers are responsible, but also and above all the manufacturers of end products such as computers, laptops, smartphones, tablets, printers and other WLAN devices. A hardware update is not necessary, but a software update, which can basically be offered and distributed very quickly. So, no matter which devices you use, keep your smartphone, tablet and notebook up to date and activate the automatic updates of the system for the near future.

What should I do, how do I stay safe?

At this point one could point out sources that describe how exactly the security hole works, how one can hack oneself and how one can use KRACK for attacks. However, I don't want to open the door to opportunistic hackers. So here are a few tips that you can follow without understanding the WPA2 security vulnerability KRACK down to the smallest detail:

• Avoid public WiFi networks. This also applies to the hotspots of network operators such as Telekom or technology giants such as Google. The best thing to do is to switch off the WiFi function completely when you're out and about. (Instructions: Deactivate WiFi under iOS 11)
• Whether active data exchange (personal data, account data, files such as photos and videos) or simply calling up a website: make sure that the service is secure. As with this blog, you will find the reference to a secure connection in the address bar of the browser: HTTPS
• If you use a secure (and therefore probably chargeable) VPN service, leave it activated permanently. Signing up head over heels with a free VPN provider does not do much if it cannot offer optimal data security.
• If possible, do without the WLAN connection and use an Ethernet or LAN connection with the respective network / router. Since the KRACK security vulnerability only relates to 802.11 WiFi connections, you are safe with wired internet.
• Keep an eye out for updates or contact the manufacturer of your devices for an update regarding the KRACK security hole in WPA2.

Is KRACK dangerous for macOS, iOS, watchOS, and tvOS?

Since Monday, October 16, 2017, Apple has released beta versions for iPhone, iPad and iPod with iOS, for Mac, iMac and MacBook with macOS as well as for watchOS on the Apple Watch and for tvOS beta versions, which contain a fix / patch for the Have problem. The online magazine iMore Apple has confirmed its knowledge of the KRACK vulnerability and the corresponding counter-work:

"Apple is deeply committed to protecting our customers' data. The fix for the KRACK WLAN vulnerability is currently in the beta of iOS, macOS, watchOS and tvOS and will be delivered to customers soon."

If you do not want to install the developer betas for developers or the public beta versions, but only want to stick to official updates, then you should also note the tips mentioned above. Soon, however, the betas should result in proper updates, which will then fully protect you again. Apple is on to it.

Spatial proximity: the most important requirement

If you use your WiFi in your house in the country, then you don't need to worry. As it results from WLAN technology and as can be read in many media, attackers who want to hack your WLAN devices via KRACK vulnerabilities need a certain spatial proximity. In a public café, in an apartment building, in the neighborhood, in an office complex or at the train station hotspot, you are more likely to be at risk.

Johannes Domke

After graduating from high school, Johannes completed an apprenticeship as a business assistant specializing in foreign languages. But then he decided to research and write, which resulted in his independence. For several years he has been working for Sir Apfelot, among others. His articles include product introductions, news, manuals, video games, consoles, and more. He follows Apple keynotes live via stream.