ieee80211_input.c in MadWifi before 0.9.3 does not properly process Channel Switch Announcement Information Elements (CSA IEs), which allows remote attackers to cause a denial of service (loss of communication) via a Channel Switch Count less than or equal to one, triggering a channel change.
http://www.vupen.com/english/advisories/2007/1187
http://www.ubuntu.com/usn/usn-479-1
http://www.securityfocus.com/bid/23436
http://www.securityfocus.com/archive/1/466689/30/6900/threaded
http://www.novell.com/linux/security/advisories/2007_14_sr.html
http://www.mandriva.com/security/advisories?name=MDKSA-2007:082
http://security.gentoo.org/glsa/glsa-200704-15.xml
http://secunia.com/advisories/26083
http://secunia.com/advisories/25861
http://secunia.com/advisories/24931
http://secunia.com/advisories/24841
http://secunia.com/advisories/24670