Rogue access point

A rogue access point is a wireless access point that has been installed on a secure network without explicit authorization from a local network administrator, whether added by a well-meaning employee or by a malicious attacker.

Although it is technically easy for a well-meaning employee to install a "soft access point" or an inexpensive wireless router - perhaps to make access from mobile devices easier - it is likely that they will configure this as "open", or with poor security, and potentially allow access to unauthorized parties.

If an attacker installs an access point they are able to run various types of vulnerability scanners, and rather than having to be physically inside the organization, can attack remotely - perhaps from a reception area, adjacent building, car park, or with a high gain antenna, even from several miles away.

To prevent the installation of rogue access points, organizations can install wireless intrusion prevention systems to monitor the radio spectrum for unauthorized access points.

Presence of a large number of wireless access points can be sensed in airspace of a typical enterprise facility. These include managed access points in the secure network plus access points in the neighborhood. A wireless intrusion prevention system facilitates the job of auditing these access points on a continuous basis to learn whether there are any rogue access points among them.

In order to detect rogue access points, two conditions need to be tested:

The first of the above two conditions is easy to test - compare wireless MAC address (also called as BSSID) of the access point against the managed access point BSSID list. However, automated testing of the second condition can become challenging in the light of following factors: a) Need to cover different types of access point devices such as bridging, NAT (router), unencrypted wireless links, encrypted wireless links, different types of relations between wired and wireless MAC addresses of access points, and soft access points, b) necessity to determine access point connectivity with acceptable response time in large networks, and c) requirement to avoid both false positives and negatives which are described below.

False positives occur when the wireless intrusion prevention system detects an access point not actually connected to the secure network as wired rogue. Frequent false positives result in wastage of administrative bandwidth spent in chasing them. Possibility of false positives also creates hindrance to enabling automated blocking of wired rogues due to the fear of blocking friendly neighborhood access point.

...
Wikipedia