Cisco IOS 12.3 and 12.4 on Aironet access points allows remote attackers to cause a denial of service (radio-interface input-queue hang) via IAPP 0x3281 packets, aka Bug ID CSCtc12426.
http://www.cisco.com/en/US/docs/wireless/access_point/ios/release/notes/12_3_8_JED1rn.html