Research Finds Critical Flaws in Wi-Fi Client Isolation

New academic research reveals that a core Wi-Fi security feature relied upon by home, enterprise, and public networks can be bypassed in practice — even when modern encryption is enabled.

The study, AirSnitch: Demystifying and Breaking Client Isolation in Wi-Fi Networks, shows that client isolation, a mechanism meant to prevent Wi-Fi users from attacking one another, is inconsistently implemented across vendors and often fails to provide the protection organizations expect.

Client isolation is designed to block direct communication between devices on the same network, reducing the risk of spying or traffic manipulation. However, the researchers found that the feature is not standardized, leading to gaps attackers can exploit.

Key weaknesses include:

• Improper handling of encryption keys used for broadcast traffic
• Isolation enforced at only one network layer instead of end-to-end
• Poor synchronization of device identity across the network stack

These flaws allow attackers connected to the same Wi-Fi network to bypass isolation controls.

By combining these weaknesses, the researchers demonstrated practical attacks that restore full man-in-the-middle capabilities — even though legacy techniques like ARP spoofing are blocked by modern defenses. In testing, every evaluated router and enterprise network was vulnerable to at least one attack variant.

Once positioned between a victim and the network, an attacker could intercept, manipulate, or observe traffic, and potentially exploit additional software vulnerabilities.

Enterprise Networks Not Immune

The findings are particularly concerning for enterprise environments using WPA3-Enterprise authentication. These networks are often viewed as highly secure but the research suggests they may offer a false sense of protection when client isolation is relied upon as a primary safeguard.

The underlying issues stem partly from outdated hardware designs and fragmented vendor implementations, meaning fixes may require more than simple software patches. The team has disclosed its findings to vendors and is calling for stronger standards and more consistent isolation enforcement.

The AirSnitch research serves as a reminder that Wi-Fi security features should not be assumed effective simply because they are widely deployed, especially in shared or high-value environments.