IP Library Granted Patent US 9,949,131
Granted Patent B2
US 9,949,131 · App. 15/586,873 · Granted Apr 17, 2018

Deauthenticating and disassociating unauthorized access points with spoofed management frames

Inventors: Mohan Ram (Bangalore, IN); Anil Kaushik (Marathalli Bangalore, IN)
Assignee: Fortinet, Inc.
H04W12/08H04W12/12H04W88/08
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Quick Facts
Patent No.
US 9,949,131
App. No.
15/586,873
Granted
Apr 17, 2018
Kind
B2
Abstract

A spoofed management frame is sent to an unauthorized access point (AP) on behalf of a station from an authorized AP, using a media access control (MAC) address of the station. The spoofed frame triggers a security association (SA) query from an unauthorized AP to reestablish valid communications. An acknowledgment (ACK) frame sent from the client to the unauthorized AP responsive to the SA query request is detected by the AP. A probe response is sent to the client. The probe response includes a channel switching element. The channel switching prevents the client from completing the SA process before a time out.

Claims (45)

1. A computer-implemented method in a station of a wireless network, the method comprising:

receiving a dissociation request from an access point (AP) on behalf of an unauthorized AP;

sending an association request to the unauthorized AP using a media access control (MAC) address of the station as a source address, wherein the request triggers a security association (SA) query from the unauthorized AP;

detecting an acknowledgment (ACK) frame sent from the unauthorized AP responsive to the SA query request; and

responsive to the ACK frame detection, receiving a probe response to the station from the AP, wherein the probe response includes a channel switching element, said channel switching element preventing the station from completing the SA process with the unauthorized AP before a time out.

2. The method of claim 1 , wherein:

sending the association request comprises sending the association request operating under Institute of Electrical and Electronics Engineers (IEEE) 801.11w protocol that allows for unprotected requests.

3. The method of claim 1 , wherein:

sending the association request comprises sending the association request as an unprotected association request to the unauthorized AP operating under Institute of Electrical and Electronics Engineers (IEEE) 801.11w protocol that allows unprotected association requests, to trigger the SA request sent from the unauthorized AP for reestablishing valid communications,

wherein protected communications are encrypted.

4. The method of claim 1 , wherein:

sending the probe response to the station comprises sending an unprotected probe response to the station operating under Institute of Electrical and Electronics Engineers (IEEE) 801.11w protocol that allows unprotected probe responses,

wherein protected communications are encrypted.

5. The method of claim 1 , further comprising:

analyzing one or more beacon frames within range of the authorized AP to determine one or more basic service set identifiers (BSSIDs); and

detecting an unauthorized BSSID.

6. The method of claim 5 , wherein:

receiving a list of authorized BSSIDs from a controller that manages APs on the wireless network; and

detecting the unauthorized BSSID comprises comparing the one or more BSSIDs against the list of authorized BSSIDs.

7. The method of claim 5 , wherein:

generating the association request using a BSSID from the one or more BSSIDs that is associated with the unauthorized AP.

8. The method of claim 5 , wherein:

generating the probe response comprises generating the response probe using a BSSID from the one or more BSSIDs that is associated with the unauthorized AP.

9. The method of claim 1 , wherein the channel switch element comprises a channel switch announcement information element, and the method further comprises:

configuring the switch element by setting a channel switch mode field of the probe response to a value of 1 to stop the station from transmitting to the unauthorized AP until a channel switch has occurred.

10. The method of claim 9 , wherein:

configuring the switch element comprises setting a channel switch count field to a value of 0 for an immediate channel switch.

11. The method of claim 9 , wherein:

detecting a channel being used by the unauthorized AP for communications with the station,

wherein configuring the switch element comprises setting a channel number field to a channel not being used by the unauthorized AP for communications with the station.

12. The method of claim 1 , wherein:

sending the channel switching element prevents the station from completing the SA process with the unauthorized AP before a time out so that the unauthorized AP deletes a security association with the station.

13. The method of claim 12 , wherein:

sending the channel switching element prevents the station from completing the SA process with the unauthorized AP before a time out so that the unauthorized AP disassociates from the station.

14. A non-transitory computer-readable medium storing instructions that, when executed by a processor, perform a computer-implemented method a station of a wireless station, the method comprising:

receiving a dissociation request from an access point (AP) on behalf of an unauthorized AP;

sending an association request to the unauthorized AP using a media access control (MAC) address of the station as a source address, wherein the request triggers a security association (SA) query from the unauthorized AP;

detecting an acknowledgment (ACK) frame sent from the unauthorized AP responsive to the SA query request; and

responsive to the ACK frame detection, receiving a probe response to the station from the AP, wherein the probe response includes a channel switching element, said channel switching element preventing the station from completing the SA process with the unauthorized AP before a time out.

15. A computer-implemented method in a station of a wireless network, the method comprising:

receiving a dissociation request from an access point (AP) on behalf of an unauthorized AP;

sending an unprotected association request to the unauthorized AP to the client using a media access control (MAC) address of the unauthorized AP as a source address, wherein the request triggers a security association (SA) query from the unauthorized AP;

detecting an acknowledgment (ACK) frame sent from the unauthorized AP responsive to the SA query request;

responsive to the ACK frame detection, receiving a probe response to the station from the AP, wherein the probe response includes a channel switching element, said channel switching element preventing the station from completing the SA process with the unauthorized AP before the time out; and

sending an unprotected dissociation/deauthentication request.

Assignments (2)
MERGER Recorded Feb 28, 2018
From: MERU NETWORKS, INC.
To: FORTINET, INC
Reel/Frame 045474/0392 →
MERGER Recorded Jan 23, 2018
From: MERU NETWORKS, INC.
To: FORTINET, LLC
Reel/Frame 045112/0786 →
Continuity (2)
Continuation 13936213 · Jul 8, 2013
Related Publication 20170303130A1 · Oct 19, 2017