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.
MadWifi before 0.9.3 does not properly handle reception of an AUTH frame by an IBSS node, which allows remote attackers to cause a denial of service (system crash) via a certain AUTH frame.