Examice

Exam CWNA-108 All QuestionsBrowse all questions from this exam

Question 25

You are the network administrator for ABC Company. Your manager has recently attended a wireless security seminar. The seminar speaker taught that a wireless network could be hidden from potential intruders if you disabled the broadcasting of the SSID in Beacons and configured the access points not to respond to Probe Request frames that have a null SSID field.

Your manager suggests implementing these security practices. What response should you give to this suggestion?

Any 802.11 protocol analyzer can see the SSID in clear text in frames other than Beacons frames. This negates any security benefit of trying to hide the SSID in Beacons and Probe Response frames.

To improve security by hiding the SSID, the AP and client stations must both be configured to remove the SSID from association request and response frames. Most WLAN products support this.

Any tenants in the same building using advanced penetration testing tools will be able to obtain the SSID by exploiting WPA EAPOL-Key exchanges. This poses an additional risk of exposing the WPA key.

This security practice prevents manufacturers' client utilities from detecting the SSID. As a result, the SSID cannot be obtained by attackers, except through social engineering, guessing, or use of a WIPS.

Correct Answer: A

Disabling the broadcasting of the SSID and configuring access points not to respond to Probe Request frames that have a null SSID field does not provide significant security benefits. Any 802.11 protocol analyzer can capture wireless frames other than Beacon frames, where the SSID is still transmitted in clear text. Thus, determined attackers can still obtain the SSID using proper tools regardless of these measures.

Discussion

Alonzo_HarrisOption: A

Although implementing a closed network may hide your SSID from some of these WLAN discovery tools, anyone with a layer 2 wireless protocol analyzer can capture the frames transmitted by any legitimate end user and discover the SSID, which is transmitted in clear-text. In other words, a hidden SSID can be found, usually in seconds, with the proper tools. Many wireless professionals will argue that hiding the SSID is a waste of time, whereas others view a closed network as just another layer of security. CWNA - 108, Sybex, pg 736