Heap-based buffer overflow in the dcerpc_read_ncacn_packet_done function in librpc/rpc/dcerpc_util.c in winbindd in Samba 3.x before 3.6.22, 4.0.x before 4.0.13, and 4.1.x before 4.1.3 allows remote AD domain controllers to execute arbitrary code via an invalid fragment length in a DCE-RPC packet.