Researcher discovers security flaws in Wi-Fi networks affecting millions of devices

Wireless network technologies have opened doors to remote attacks that can harm users without them realizing it. The hardware for wireless connection of the devices are extremely complex, so it is not uncommon for failures to be found and quickly corrected by manufacturers.

A Belgian security researcher details the security flaws of the Wi-Fi standard he found on routers and other devices on his blog. According to him, the bugs leave smartphones, notebooks and other devices equipped with technology susceptible to hacker intrusions.

Some of these vulnerabilities, however, depend on the interaction between the user and the criminal, which prevents this type of attack from being more frequent. As he explains, there are flaws in the development of the Wi-Fi standard that can be used by addressing a malicious DNS server.

On the other hand, device programming errors can be more worrisome. For example, during the process by which Wi-Fi breaks and reassembles data packets to transmit them to other users, it allows a criminal to intercept them and inject malicious code before they reach the receiver.

The discovered vulnerabilities affect all modern security protocols of Wi-Fi, including the latest WPA3 specification. Even the original security protocol of Wi-Fi, called WEP, is affected. This means that several of the newly discovered design flaws have been part of Wi-Fi since its release in 1997! Fortunately, the design flaws are hard to abuse because doing so requires user interaction or is only possible when using uncommon network settings. As a result, in practice the biggest concern are the programming mistakes in Wi-Fi products since several of them are trivial to exploit.

Mathy Vanhoef

These failures allow a series of attacks, called FragAttacks (fragmentation and aggregation attacks), to pose risks even for devices that adopt the WPA3 protocol,responsible for making Wi-Fi networks more secure.

Experiments the Belgian researcher also involved in the research of the KRACKattacks, showed that two out of four domestic routers tested were susceptible to FragAttacks, as well as several smartphones and IoT devices.

In light of the findings, the Wi-Fi Alliance issued a statement easing concerns about security breaches.

There is no evidence of vulnerabilities being used against Wi-Fi users maliciously, and these issues are mitigated through routine device updates that allow detection of suspicious transmissions or improve their support for security implementation best practices.

Wi-Fi Alliance

In fact, Vanhoef reports that these vulnerabilities have greater risk potential on devices that no longer have manufacturer support or are outdated at customer’s option. For information, more than 100 million active PCs ran Windows 7 in the late 2020 estimates.

It is worth noting that most of these older devices rely on the WPA2 Wi-Fi network protocol, which does not offer the same level of encryption and protection on public networks as the successor generation. Therefore, it is important that manufacturer updates are respected so that Wi-Fi Alliance forecasts are factual.

More Information

• FragAttacks
• Fragment and Forge: Breaking Wi-Fi Through Frame Aggregation and Fragmentation (PDF)