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.

The following software releases have been updated to resolve this specific issue:

Junos OS Evolved: 21.4R3-S9-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO, 22.4R3-S2-EVO, 23.2R2-EVO, 23.4R1-S1-EVO, 23.4R2-EVO, 24.2R1-EVO, and all subsequent releases.

This issue is being tracked as 1786574 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

There are no known workarounds for this issue.

2024-10-09: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team