Wireless Vulnerabilities & Exploits
Wireless Vulnerabilities & Exploits
WVE ID: WVE-2005-0033
Type: Vulnerability
Status: Candidate
Classification:
Denial of Service
Design Flaw
Description:
The 802.11 DSSS PHY is vulnerable to DoS attacks against the CSMA/CCA mechanism for controlling access to the wireless medium.
Discussion:
The 802.11 DSSS physical layer utilizes CSMA/CCA (Carrier Sense Multiple Access/Clear Channel Assessment) to ensure that no two wireless devices on the same channel transmit simultaneously. If two stations were to transmit at the same time, then they would interfere with each other and the data from each station would need to be re-transmitted.
CSMA/CCA deters collisions by requiring stations to monitor the channel and avoid transmitting while another one is doing so. However, it is possible for any station to perform a denial of service (DoS) attack by exploiting the CSMA/CCA algorithm to prevent all other devices on the channel from transmitting. This is done by putting a wireless device into PLME_DSSSTESTMODE, saturating the channel by continuously transmitting. All other CSMA/CCA stations find the channel busy and avoid transmitting.
Devices utilizing OFDM (Orthogonal Frequency Division Multiplexing) are not vulnerable to this attack. This includes 802.11a devices as well as 802.11g devices locked to use a higher rate which utilizes OFDM.
Credits
Author:
Jason
Smith
(j4.smith)
: Queensland University of Technology
Author:
Mark
Looi
(m.looi@qut.edu.au)
: Queensland University of Technology
Author:
Chris
Wullems
(c.wullems@qut.edu.au)
: Queensland University of Technology
Author:
Kevin
Tham
(wk.tham@qut.edu.au)
: Queensland University of Technology
References
URL:
http://www.auscert.org.au/render.html?it=4091
URL:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-0459
URL:
http://www.kb.cert.org/vuls/id/106678
URL:
http://www.isrc.qut.edu.au/resource/techreport/wireless/
URL:
http://standards.ieee.org/getieee802/download/802.11-1999.pdf
Released: 2004-05-13
Submitter
Andrew
Lockhart
(alockhart@networkchemistry.com)
: Network Chemistry
Submitted: Sun Nov 06 00:27:41 -0800 2005
Candidate Date: Mon Nov 07 12:51:16 -0800 2005
