An Improper Restriction of Communication Channel to Intended Endpoints vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on ACX 7000 Series allows an unauthenticated, network based attacker to cause increased consumption of resources, ultimately resulting in a Denial of Service (DoS). When specific transit MPLS packets are received by the PFE, these packets are internally forwarded to the Routing Engine (RE), rather than being handled appropriately. Continuous receipt of these MPLS packets causes resources to be exhausted.

MPLS config is not required to be affected by this issue. This issue affects Junos OS Evolved ACX 7000 Series: All versions before 21.4R3-S9-EVO, 22.2-EVO before 22.2R3-S4-EVO, 22.3-EVO before 22.3R3-S3-EVO, 22.4-EVO before 22.4R3-S2-EVO, 23.2-EVO before 23.2R2-EVO, 23.4-EVO before 23.4R1-S1-EVO, 23.4R2-EVO.