Junos OS Evolved: ACX7024, ACX7100-32C and ACX7100-48L: Traffic stops when a specific IPv4 UDP packet is received by the RE

A NULL Pointer Dereference vulnerability in Juniper Networks Junos OS Evolved on ACX7024, ACX7100-32C and ACX7100-48L allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). If a specific IPv4 UDP packet is received and sent to the Routing Engine (RE) packetio crashes and restarts which causes a momentary traffic interruption. Continued receipt of such packets will lead to a sustained DoS. This issue does not happen with IPv6 packets. This issue affects Juniper Networks Junos OS Evolved on ACX7024, ACX7100-32C and ACX7100-48L: * 21.4-EVO versions earlier than 21.4R3-S6-EVO; * 22.1-EVO versions earlier than 22.1R3-S5-EVO; * 22.2-EVO versions earlier than 22.2R2-S1-EVO, 22.2R3-EVO; * 22.3-EVO versions earlier than 22.3R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions earlier than 21.4R1-EVO.