A Use of Uninitialized Resource vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX4700 devices allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). When forwarding-options sampling is enabled, receipt of any traffic destined to the Routing Engine (RE) by the PFE line card leads to an FPC crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of any traffic leading to the RE by the PFE line card will create a sustained Denial of Service (DoS) condition to the PFE line card. This issue affects Junos OS on SRX4700:  * from 24.4 before 24.4R1-S3, 24.4R2 This issue affects IPv4 and IPv6.