Race condition in the Common Classification Engine (CCE) in the Measurement, Aggregation, and Correlation Engine (MACE) implementation in Cisco IOS 15.4(2)T3 and earlier allows remote attackers to cause a denial of service (device reload) via crafted network traffic that triggers improper handling of the timing of process switching and Cisco Express Forwarding (CEF) switching, aka Bug ID CSCuj96752.