Wireless Vulnerabilities & Exploits
Wireless Vulnerabilities & Exploits
WVE ID: WVE-2005-0045
Type: Vulnerability
Status: Candidate
Classification:
Denial of Service
Design Flaw
Description:
802.11 networks are vulnerable to DoS attacks that involve sending Deauthentication frames to a station or network.
Discussion:
802.11 networks utilize frames to manage connection and disconnection of stations from a wireless network. These are appropriately called management frames. One type of management frame, a deauthentication frame is used to deauthenticate a station from a wireless network and may be sent by a station or an Access Point.
There are several reasons for sending these frames, ranging from the station leaving the network to the authentication of the receiving station no longer being valid. Once a station receives a deauthentication frame from the AP it is disconnected from the network.
However, a problem arises in that 802.11 management frames provide no authentication. Hence it is possible for an attacker to spoof a legitimate AP's BSSID to send deauthentication frames to a station. This of course will cause the station to disconnect from the network at which point it will attempt to reconnect.
If the attacker sends the deauthentication frames at a high rate the station will receive another deauthentication before it finishes authenticating and associating with the legitimate AP. Thus, the station is blocked from using the network until the attacker stops transmitting the deauthentication frames.
It is also possible to target an entire wireless network by sending the deauthentication frames to the broadcast address (FF:FF:FF:FF:FF:FF) instead of directing them to an individual station. This will cause all stations on the network to be disconnected -- using only one deauthentication frame.
Credits
References
URL:
http://standards.ieee.org/getieee802/download/802.11-1999.pdf
WVE:
WVE-2005-0019
Released: 2000-01-01
Submitter
Andrew
Lockhart
(alockhart@networkchemistry.com)
: Network Chemistry
Submitted: Wed Nov 30 11:31:32 -0800 2005
Candidate Date: Wed Nov 30 11:33:44 -0800 2005
