Vulnerabilities in WPA2


What exactly is going on?
Security researchers have developed a new attack on WPA2 (the most common security protocol for wireless networks). With this new attack, they have succeeded in breaking the security offered by WPA2 or injecting packets to intercept wireless network traffic. This attack has been dubbed “KRACK” (Key Reinstallation Attack). In simple terms, what this comes down to is that a number of vulnerabilities allow WPA2 security to be partially or completely circumvented.

How serious is KRACK?
KRACK is very serious because it gets at the heart of WPA2, the security protecting wireless networks. KRACK bypasses this security and makes it possible to intercept network traffic that should actually be secure.

The vast majority of wireless networks worldwide use WPA2, hence they are potentially affected. There are also “open” wireless networks that are not protected, and wireless networks that use older, even less secure, forms of security. These are not affected by this issue.

Is WPA2 encryption now worthless?
No, the attack itself is directed against the structure of the encryption, not the encryption itself. While it does render the current implementations of WPA2 as good as worthless against an attacker with the right knowledge and motive, the problems in WPA2 are relatively easy to remedy.

Are all wireless access points and mobile devices that use WPA2 affected?
Yes, virtually all wireless access points and mobile devices that use WPA2 are affected. However, the impact goes even further: other equipment that uses WPA2, like printers, toothbrushes, washing machines, scales, TVs, audio equipment, and even medical equipment are also affected.

The researchers have indicated specifically that big-name manufacturers like Android, Linux, Windows, and Apple are all affected. CERT/CC is maintaining a master list.

What needs to happen now?
The vulnerability in WPA2 can be repaired. This will keep the attacks from being successful. Vendors of equipment and software developers will have to create a security update for their own products and make it available to their customers. This update will then have to be installed on the affected devices to prevent this type of attack.

If WPA2 can be patched, can the affected devices be updated?
This investigation has been known for some time. Prior to publication, the researchers informed vendors, a number of which have already released an update. Some of them have already rolled it out.

Many users will not update; what does that mean for Wifi?
This is correct. In practice, security updates are not installed at all consistently. For Wifi, this means that if protection of the information you are sending over a wireless network is truly important, you cannot assume that any wireless network is secure if you are not in control of both ends of the connection. Even better would be to not depend on the security of the underlying wireless network, but to take action to secure your data yourself, for example, by using a VPN service.

Are there secure alternatives to WiFi?
There are no security alternatives for WiFi. Switching to 4G is an option. For the average attacker, it is many times more difficult to intercept 4G traffic. But here again, if security of your data is truly important, use your own encryption (VPN) in addition to 4G.

If you are using a VPN, are you vulnerable to KRACK?
To some extent, yes. Ultimately, it could allow access to any internal network, even if you are browsing the web or connecting to your office through a VPN.

Who is responsible for KRACK?
No one. WPA2 was developed by the security community in a manner that we know can be implemented securely. Errors can always happen, but the expectation is that this is not a major problem.

These vulnerabilities in WPA2, which are very serious, are the first to be discovered in many years. They will entail costs for many parties: manufacturers who have to update their products, consumers and businesses that will have to invest time in installing updates, and the parties that in the future may face a serious attack via KRACK.

What impact does a phenomenon like KRACK have on the new government’s intention to hold the vendors responsible for software bugs and data leaks?
KRACK certainly relates to this issue, but in fact goes one level deeper. If you think of the automotive industry, it seems obvious to hold manufacturers responsible for producing safe cars. But if it were to suddenly become apparent that steel was a lot less strong than had always been thought, this would hardly be something you could hold the manufacturers responsible for.

The line might not be able to be drawn in black and white, but if manufacturers themselves introduce bugs or use problem software provided by others, there would conceivably be some liability issues. This is much less the case where a manufacturer uses protocols and standards that later prove to be insecure; fortunately, this happens much less often.

Can Fox-IT determine whether a Wifi connection has been compromised by KRACK?
In theory, this can be discovered by analysing the data travelling over the wireless connection, and potentially by checking the system logs, although we do not yet know this for sure.

What does Fox-IT recommend that Wifi users do right now?
For businesses, if confidentiality of your data is critical and you have to send information over a wireless network at any time, use encryption that you yourself control. This allows you to secure your data end-to-end.

For home users, the same principle applies: if security of your data is critical, use a VPN. Also be sure to install all available updates for your devices as quickly as possible to prevent attacks.

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