The sctp_sf_do_5_2_4_dupcook function in net/sctp/sm_statefuns.c in the SCTP implementation in the Linux kernel before 3.8.5 does not properly handle associations during the processing of a duplicate COOKIE ECHO chunk, which allows remote attackers to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via crafted SCTP traffic.