CVE-2023-44190: Juniper Junos OS Evolved

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

An Origin Validation vulnerability in MAC address validation of Juniper Networks Junos OS Evolved on PTX10001, PTX10004, PTX10008, and PTX10016 devices allows a network-adjacent attacker to bypass MAC address checking, allowing MAC addresses not intended to reach the adjacent LAN to be forwarded to the downstream network. Due to this issue, the router will start forwarding traffic if a valid route is present in forwarding-table, causing a loop and congestion in the downstream layer-2 domain connected to the device. This issue affects Juniper Networks Junos OS Evolved on PTX10001, PTX10004, PTX10008, and PTX10016: * All versions prior to 21.4R3-S5-EVO; * 22.1 versions prior to 22.1R3-S4-EVO; * 22.2 versions 22.2R1-EVO and later; * 22.3 versions prior to 22.3R2-S2-EVO, 22.3R3-S1-EVO; * 22.4 versions prior to 22.4R2-S1-EVO, 22.4R3-EVO; * 23.2 versions prior to 23.2R1-S1-EVO, 23.2R2-EVO.

Affected products

• Juniper Junos OS Evolved: before 21.4 (fixed in 21.4); version 21.4 only; version 22.1 only; version 22.2 only; version 22.3 only; version 22.4 only; …

Published 2023-10-11. Last modified 2026-06-17.