Deauthentication/Disassociation attack

Deauthentication/Disassociation attack is a part of the Denial-of-Service attacks. Attackers may also use this attack in order to recover hidden ESSIDs or to capture WPA/WPA2 handshakes by forcing victims to re-authenticate. This attack can be used only if there is at least one client connected to the access point.

The client is connected to the wireless router. The attacker will try to deauthenticate the client by using airodump-ng and aireplay-ng. Both tools are included in the Backtrack 5 r3 OS.The following steps describe the process of the attack. After the attacker has set the wireless network card in monitor mode he searches for access points in range. The complete command is the following:

  • airodump-ng mon0

Where airodump-ng is the tool and mon0 is the monitor interface. The result of this command is shown in the next screenshot.

Screenshot0202

At this point the attacker has information about the wireless router (ESSID, Channel, BSSID etc). The next step is to find the clients that are connected to the access point with ESSID GeorgeLab. To find this information he will use the following command:

  • airodump-ng mon0 -c 1 –bssid 00:05:59:49:A7:A0

Where airodump-ng is the tool, mon0 the interface, -c the channel and –bssid the MAC address of the access point. The result is shown in the next figure.

Screenshot0303

The figure above shows that there is one client connected with MAC address 00:13:CE:AC:70:BE.

Now the last step is to disassociate the client. To achieve this, the following command is used:

  • aireplay-ng -0 1000 -a  00:05:59:49:A7:A0 -c 00:13:CE:AC:70:BE mon0

Where aireplay-ng is the tool, -0 the parameter for the Deauthentication attack, 1000 is the number of deaths, -a the MAC address of the wireless router, –c the MAC address of the client and mon0 the interface. The result of the command is shown in the next screenshot.

Screenshot04

The above screenshot shows that the attack is performed succesfully. The client is disconnected from the network and cannot establish a connection until the attacker stops sending Deauthentication messages.

Advertisements

3 thoughts on “Deauthentication/Disassociation attack

  1. Very informative guide, well done!! I have a question though, you have to do this on each connected client? There is any way to deauth multiple clients by once running the commands above or you have to do only to individual clients?

    • @Jsiak, this attack can be carried out on either one or all clients connected to the access point. Using the above example, you would just remove the destination MAC address of the specific client you want to deauthenticate. Because no specific destination MAC address associated with the client is specified, the following command would deauthenticate all clients connected to the access point:

      aireplay-ng -0 1000 -a 00:13:CE:AC:70:BE -c mon0

      More information about this attack can be found online at http://www.aircrack-ng.org/doku.php?id=deauthentication

      • Very helpful article. One note though, in your aireplay line, the MAC addresses seem to be the wrong way round.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s