SRX Series: If UTM Enhanced Content Filtering and AntiVirus are enabled, and specific traffic is processed the PFE will crash

An Unchecked Return Value to NULL Pointer Dereference vulnerability in Packet Forwarding Engine (PFE) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). On SRX Series if Unified Threat Management (UTM) Enhanced Content Filtering (CF) and AntiVirus (AV) are enabled together and the system processes specific valid transit traffic the Packet Forwarding Engine (PFE) will crash and restart. This issue affects Juniper Networks Junos OS 21.4 versions prior to 21.4R1-S2, 21.4R2 on SRX Series. This issue does not affect Juniper Networks Junos OS versions prior to 21.4R1.