What is the WPA2 KRACK exploit and is SonicWall vulnerable?

On October 16 2017 security researchers made public earlier findings in which they demonstrated fundamental design flaws in WPA2 that could theoretically lead to man-in-the-middle (MITM) attacks using key reinstallation attacks (KRACKs). Exploiting the vulnerability could enable cyber criminals to steal confidential information such as email, credit card numbers, passwords and more.

The WPA2 design flaws are protocol vulnerabilities and are not implementation specific. Both wireless access points and wireless clients are susceptible.

Impact to SonicWall customers

SonicWall Capture Labs has evaluated these vulnerabilities and determined that our SonicPoint and SonicWave wireless access points, as well as our TZ and SOHO Wireless firewalls, are not vulnerable to the flaws in WPA2.

SonicWall is working on a solution to provide an additional layer of protection for SonicWall customers that will block these man-in-the-middle attacks even from vulnerable unpatched clients. This will be delivered in a future SonicOS update. 

Additional FAQs:

1. Can KRACK be launched remotely?
   NO. The attacker needs to be physically present near the targeted equipment. It is required to have an active antenna within range of the targeted wireless network point to intercept the Internet traffic.
2. How is the attack launched?
   The hacker interferes with the initial “four-way handshake” between client and the Wi-Fi router (when stablishing connection) in a way that allows the attacker to gain an ability to decrypt the traffic you exchange over Wi-Fi.
   
3. Could KRACK expose any private information?
   Yes. By hijacking an unsecure connection, the attacker can steal sensitive information (credit card numbers, passwords, messages, emails, etc.). A malicious actor could also gain unauthorized access, manipulate data, and inject ransomware or other malware into websites.
4. What is the scope of KRACK impact?
   It potentially affects everyone who is connected to Wi-Fi using WPA/WPA2 encryption. The attack can affect both Wi-Fi infrastructures (Access Points & Controllers) as well as Wi-Fi clients.
5. If not affected by KRACK, why is there a SonicOS firmware patch?
   A compromised client can still issue a rekey to the access point or firewall that can be intercepted by the attacker. In order to block the unsafe communication, the wireless controller or access point forces nonce not to be reused in rekey request.
6. Should I upgrade SonicOS on my firewall?
   Upgrading SonicOS firmware is recommended to mitigate the risks from vulnerable wireless clients connecting to a SonicWall standalone or integrated AP.
7. How can I secure my wireless clients?
   Most vendors have already provided a security patch or working to provide one. Make sure your device has been upgraded to the latest security patch provided by device vendor.
8. Where can I get more info on KRACK?
   Link to research paper: https://papers.mathyvanhoef.com/ccs2017.pdf
   Also, https://www.krackattacks.com/

Recommended Action

In order to minimize the potential impact of these vulnerabilities, SonicWall recommends customers take the following actions:

• Patch all Windows, Linux, Android, iOS and Mac OS clients with the latest KRACK updates from client vendors.
• For additional security, customers can use SonicWall VPN technology to encrypt all network traffic between their wireless clients and the SonicWall firewall.
  • For SSL encryption on mobile devices, use the SonicWall Mobile Connect client, available from the Apple App Store, Google Play, the Windows Phone Store or the Chrome Web Store https://www.sonicwall.com/products/remote-access/vpn-clients
  • For IPSec encryption, use the SonicWall Global VPN Client https://www.sonicwall.com/en-us/support/knowledge-base/170505725970885.

Should you have further questions or need assistance, please contact your preferred SonicWall reseller or SonicWall Support. You can also expect to see a blog post about this vulnerability on https://blog.sonicwall.com/ shortly.