Juniper Junos before 10.4S14, 11.4 before 11.4R5-S2, 12.1R before 12.1R3, 12.1X44 before 12.1X44-D20, and 12.1X45 before 12.1X45-D15 on SRX Series services gateways, when a plugin using TCP proxy is configured, allows remote attackers to cause a denial of service (flow daemon crash) via an unspecified sequence of TCP packets.