A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of the Juniper Networks Junos OS on the MX Series platforms with Trio-based FPCs allows an unauthenticated, adjacent attacker to cause a Denial of Service (DoS).

In case of channelized Modular Interface Cards (MICs), every physical interface flap operation will leak heap memory. Over a period of time, continuous physical interface flap operations causes local FPC to eventually run out of memory and crash.  

List of channelized MICs include:

Below CLI command can be used to check the memory usage over a period of time:

  user@host> show chassis fpc

                Temp CPU Utilization (%)   CPU Utilization (%) Memory   Utilization (%)
  Slot State     (C)  Total  Interrupt     1min   5min   15min DRAM (MB) Heap     Buffer
  0 Online       43     41         2                           2048       49         14
  1 Online       43     41         2                           2048       49         14
  2 Online       43     41         2                           2048       49         14

This issue affects Junos OS on MX Series: 

• All versions before 21.2R3-S7, 
• from 21.4 before 21.4R3-S6, 
• from 22.1 before 22.1R3-S5, 
• from 22.2 before 22.2R3-S3, 
• from 22.3 before 22.3R3-S2, 
• from 22.4 before 22.4R3, 
• from 23.2 before 23.2R2, 
• from 23.4 before 23.4R2.

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

Junos OS: 21.2R3-S7, 21.4R3-S6, 22.1R3-S5, 22.2R3-S3, 22.3R3-S2, 22.4R3, 23.2R2, 23.4R1, 23.4R2, 24.1R1, and all subsequent releases.

This issue is being tracked as 1770750 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).

2024-10-09: Initial Publication
2024-10-15: Removed SRX4600 and SRX5K series from affected platforms

• 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