Juniper Junos 11.4 before R11, 12.1 before R9, 12.1X44 before D30, 12.1X45 before D20, 12.1X46 before D15, 12.1X47 before D10, 12.2 before R8, 12.2X50 before D70, 12.3 before R6, 13.1 before R4, 13.1X49 before D55, 13.1X50 before D30, 13.2 before R4, 13.2X50 before D20, 13.2X51 before D15, 13.2X52 before D15, 13.3 before R1, when using an em interface to connect to a certain internal network, allows remote attackers to cause a denial of service (em driver bock and FPC reset or "go offline") via a series of crafted (1) CLNP fragmented packets, when clns-routing or ESIS is configured, or (2) IPv4 or (3) IPv6 fragmented packets.