net/netfilter/nfconntrackprotodccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly, which allows remote attackers to cause a denial of service (system crash) or possibly execute arbitrary code via a DCCP packet that triggers a call to the (1) dccpnew, (2) dccppacket, or (3) dccperror function.