Discovering hidden SSIDs

Now, most network administrators think that hiding wireless SSIDs is the most robust step in protecting a network against attacks. But this is not the case because within minutes, an attacker will discover the hidden SSIDs. How does this happen? Now, from the wireless frame architecture, we know that beacon frames contain the wireless SSIDs omitted by the APs. This helps client machines or wireless cards to discover the SSIDs in the network. In a hidden SSID configuration, these beacon frames do not contain the SSIDs, hence only clients who know the SSIDs can connect to it. But this hidden SSID security can be easily bypassed.

To bypass this, we need to wait for a legitimate client to connect to the wireless network. Once the user connects, based on the probe request and response, the hidden SSID will be discovered and will be visible on screen.

Or, during wireless penetration testing, the SSIDs are usually given by the customers, and hence filters using...