Episode 17: Breaking Wi-Fi With Frame Attacks!

Cryptography FM

Wi-Fi is a pretty central technology to our daily lives, whether at home or at the office. Given that so much sensitive data is regularly exchanged between Wi-Fi devices, a number of standards have been developed to ensure the privacy and authentication of Wi-Fi communications.

However, a recent paper shows that every single Wi-Fi network protection standard since 1997, from WEP all the way to WPA3, is exposed to a critical vulnerability that allows the exfiltration of sensitive data. How far does this new attack go? How does it work? And why wasn’t it discovered before? We’ll discuss this and more in this episode of Cryptography FM.

Links and papers discussed in the show:

• Fragment and Forge: Breaking Wi-Fi Through Frame Aggregation and Fragmentation
• Dragonblood: Analyzing the Dragonfly Handshake of WPA3 and EAP-pwd
• Release the Kraken: New KRACKs in the 802.11 Standard

Music composed by Toby Fox and performed by Sean Schafianski.

Special Guest: Mathy Vanhoef.

Sponsored By:

• Capsule Social: At Capsule Social, Inc. we are building a platform for decentralized discourse. A place where content creators, writers, and thinkers have full ownership and control over their speech, and enjoy resilience from censorship and takedowns. Capsule Social is hiring decentralized technology engineers, and we'd be thrilled for you to apply.

Links:

• Fragment and Forge: Breaking Wi-Fi Through Frame Aggregation and Fragmentation — In this paper, we present three design flaws in the 802.11 standard that underpins Wi-Fi. One design flaw is in the frame aggregation functionality, and another two are in the frame fragmentation functionality. These design flaws enable an adversary to forge encrypted frames in various ways, which in turn enables exfiltration of sensitive data. We also discovered common implementation flaws related to aggregation and fragmentation, which further worsen the impact of our attacks. Our results affect all protected Wi-Fi networks, ranging from WEP all the way to WPA3, meaning the discovered flaws have been part of Wi-Fi since its release in 1997. In our experiments, all devices were vulnerable to one or more of our attacks, confirming that all Wi-Fi devices are likely affected. Finally, we present a tool to test whether devices are affected by any of the vulnerabilities, and we discuss countermeasures to prevent our attacks.
• Dragonblood: Analyzing the Dragonfly Handshake of WPA3 and EAP-pwd — We systematically analyze WPA3 and EAP-pwd, find denial-of- service and downgrade attacks, present severe vulnerabilities in all implementations, reveal side-channels that enable offline dictionary attacks, and propose design fixes which are being officially adopted.
• Release the Kraken: New KRACKs in the 802.11 Standard — We improve key reinstallation attacks (KRACKs) against 802.11 by generalizing known attacks, systematically analyzing all hand- shakes, bypassing 802.11’s official countermeasure, auditing (flawed) patches, and enhancing attacks using implementation-specific bugs.