Wi-Fi access points broadcast packets containing their SSID, BSSID, and channel information to allow devices to discover and connect. Hidden networks broadcast packets with a blank SSID field, requiring clients to actively probe by broadcasting known SSIDs to connect. These client probes are unencrypted and reveal the SSIDs of hidden networks the device has previously connected to or configured, potentially exposing sensitive information. Specialized software can detect hidden networks by their BSSID and capture SSIDs during active discovery. Research shows that many SSIDs contain personal or sensitive data, which can be harvested by attackers. Hidden SSIDs also cause performance and battery life issues, especially in the 6GHz band. Vendors like Apple and Asus recommend against using hidden SSIDs due to these risks and drawbacks.

The main impact is the unintended disclosure of hidden Wi-Fi network names and potentially sensitive personal information embedded in SSIDs, which can be intercepted by any nearby attacker due to unencrypted client probes. This exposure can facilitate targeted attacks by revealing network existence, location, and possibly passwords if encoded in SSIDs. Additionally, hidden SSIDs can degrade network performance and increase client device power consumption. However, hiding SSIDs does not prevent detection of the network or protect against attacks on weak security protocols.

Vendors such as Apple and Asus recommend against using hidden SSIDs as a security measure. Instead, users should rely on strong Wi-Fi security protocols (e.g., WPA3) and robust passwords. Avoid embedding sensitive information such as passwords, personal names, or addresses in SSIDs. There is no patch required since this is a design behavior of Wi-Fi protocols. Users should disable hidden SSID features to improve security and performance.