Junos OS is a FreeBSD-based operating system used in Juniper Networks hardware routers. It is the operating system used in Juniper Networks network routing, switching, and security devices.A denial of service vulnerability exists in the flow daemon (flowd) of the Juniper Networks Junos OS SRX300 Series, SRX500 Series, SRX1500, and SRX5000 Series. The vulnerability stems from the program not properly handling anomalous packets. An attacker could use this vulnerability to cause the flowd/srxpfe process to crash, resulting in a denial of service.