I’m the first one I have activated a guest Wi-Fi network to facilitate access to Wi-Fi connectivity for my friends and family, without compromising the security and privacy of the Wi-Fi network to which the rest of me is connected. devices in my home. The coffee shop I usually go to does it too.
Separating the main network from the one used by visitors or clients seemed enough to prevent someone connected from snooping on other people’s computers, cell phones or printers. However, that model just took a major setback.
A group of researchers has presented in the NDSS 2026 a attack called AirSnitch which shows that this separation can be broken even when the router has isolation between devices activated and uses modern encryption such as WPA2 or WPA3.
The problem with AirSnitch is that it is not a brute force attack against these protection systems, but rather it has found an alternative path in which this protection simply does not arrive.
AirSnitch is not an attack, it is an alternative
AirSnitch is not an out-of-the-box malware, but rather a technique that exploits a vulnerability in the way many access points implement client isolation. This function, present in all home, business or public Wi-Fi networks, should prevent two devices connected to the same Wi-Fi from being able to communicate directly with each other.
The problem, according to the study presented in it Network and Distributed System Security Symposiumis that this isolation is not part of a single standard and each manufacturer implements it in its own way. In their tests, the researchers analyzed 11 different devices, from home routers to professional equipment and alternative firmwares. They found vulnerabilities to AirSnitch techniques in all of them.
In statements collected by Ars TechnicaXin’an Zhou, one of the authors of the work, stated that AirSnitch “breaks Wi-Fi encryption around the world and could have the potential to enable advanced cyberattacks. Our research physically taps the entire wire for these sophisticated attacks to work. It is truly a threat to the security of networks around the world.”
How AirSnitch works
The key is that, although the devices are “isolated” from each other thanks to the customer isolationshare certain internal mechanisms of the router that allow data traffic to be organized. AirSnitch takes advantage of that feature to trick the access point and make some of the information that should go to another device pass through the attacker first.
In practice, this allows you to place yourself in the middle of the communication without the victim realizing it, generating what is known in cybersecurity as a Man-in-the-Middle (man in the middle), in which all the information on that device first passes through an intermediary. From there, the attacker can observe data and, in certain cases, modify it before it reaches its destination. That is, it is not about guessing the Wi-Fi password, but rather taking advantage of how the device itself router manages connections internal once someone is already connected.
The researchers showed that this technique can facilitate additional attacks, such as redirecting the victim to fake pages or manipulating certain internal communications if they are not adequately protected. Isolation, which was supposed to prevent precisely this scenario, stops be an effective barrier.
The main problem is that all devices connect to the same router that manages them.
Why public networks are the most delicate scenario
The risk is especially relevant in open or shared networksF for many people: cafes, airports, hotels or coworking spaces. In these environments, any user can legally connect through the password provided by the establishment and, if the access point is vulnerableattempt to exploit the flaw against other clients connected at that time.
In one home network the impact is much more limitedbecause the attacker needs to know the password to enter first. That is, it has to be one of the guests to whom you have given the password, not someone external. Still, research shows that activating a guest network does not alone ensure that devices are completely isolated.
Being a recent discovery, there is still no immediate universal solution for the end user. The fix depends largely on firmware updates by manufacturers or deeper changes in how they design their device isolation systems.
Meanwhile, in enterprise environments it is recommended to segment networks more strictly, using configurations that truly separate devices into different internal environments and do not depend solely on a router function.
For individuals, keeping equipment up-to-date, using strong passwords, and avoiding sensitive operations on public networks without additional protection are reasonable measures to reduce risk that continue to be in effect. Need a password to connect to a Wi-Fi network It is not a guarantee of security or privacy.
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Image | Unsplash (Bernard Hermant)
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