flowd in Juniper Junos 10.4 before 10.4S14, 11.4 before 11.4R8, 12.1 before 12.1R7, and 12.1X44 before 12.1X44-D15 on SRX devices, when PIM and NAT are enabled, allows remote attackers to cause a denial of service (daemon crash) via crafted PIM packets, aka PR 842253.